Methods and systems for recycling carpet and carpets manufactured from recycled material

ABSTRACT

The present invention pertains to carpet and methods of making and recycling carpet. In one aspect, the carpet includes: a primary backing which has a face and a back surface; a plurality of fibers attached to the primary backing and extending from the face of the primary backing and exposed at the back surface of the primary backing; an adhesive composition backing; and an optional secondary backing adjacent to the adhesive backing. The method of making carpet includes extrusion coating the adhesive composition onto the back surface of a primary backing to form the adhesive composition backing. The method of recycling carpet can recover one or more polymeric carpet components.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims the benefit of priorityto U.S. patent application Ser. No. 11/939,496 filed Nov. 13, 2007 nowU.S. Pat. No. 7,820,728, which application claims the benefit ofpriority to U.S. Provisional Patent Application No. 60/865,611 filedNov. 13, 2006. The entire disclosures of application Ser. No. 11/939,496and Application No. 60/865,611 are incorporated by reference herein forall purposes.

FIELD OF THE INVENTION

The present invention relates generally to methods and systems forreclaiming one or more polymer components from a carpet. The inventionalso relates to carpet comprising a post consumer carpet materialreclaimed by the methods and systems disclosed. Still further, theinvention also relates to methods for the manufacture of carpetcomprising a material reclaimed from a post consumer carpet.

BACKGROUND OF THE INVENTION

Carpet, particularly nylon carpet, is the floor covering of choice inmany households and businesses. Unfortunately, carpet has a limitedlifespan and must eventually be replaced, with the resultant used carpetwaste generally being sent to landfill. The vast quantities of carpetwaste that are generated annually are burdensome to landfill capacityand have a negative impact on the environment. Furthermore, most carpetis made with nylon as the face fiber, a material that is relativelyexpensive. The quantity of used carpet discarded every year amounts to aloss of billions of dollars in potentially reusable carpet components.

To reduce the impact of used carpet on the environment, and to reclaimsome of the financial loss due to discarding of fibers and other usefulcarpet material waste, carpet recycling would appear to be a logicalsolution. Recycling carpet, however, is difficult because its threemajor components are chemically and physically diverse. Most carpetconsists of about 20-50 weight percent face fiber, the remainder beingbacking materials, commonly polypropylene, and an adhesive whichattaches the carpet fiber to the backing material. The adhesivetypically comprises a carboxylated styrene-butadiene (XSB) latexcopolymer, and inorganic filler like calcium carbonate. Further, whilecured thermosetting systems may under certain circumstance berecoverable, they are not capable of being reused as raw polymericcomponents in the manufacture of a second generation carpet.

To recycle carpet, the face fibers are typically separated from theadhesive and backing to be reprocessed into new products or to bechemically recycled. Various methods for the mechanical removal ofcarpet fiber have been used. These methods disadvantageously result inlow yield of the recycled carpet fiber. For example, U.S. Pat. No.6,610,769 discloses a method of employing an adhesive that can becompletely removed by applying shear in the presence of an aqueousalkaline solution. In another example, U.S. Pat. No. 5,240,530 disclosesa method of grinding carpet to a fiber length of less than aboutone-quarter inch and washing in a water bath to allow the variousmaterials of the carpet to be separated by density.

In a further example, U.S. Pat. No. 5,230,473 describes a method fordisintegrating, separating, and segregating whole carpet by looseningand debonding a latex/filler binder system by repeated application ofhighly pressurized fluids consisting of air, water, heated air, steam,and chemical solutions, and repeated stripping with rotating elements.

In another example, U.S. Pat. No. 5,722,603 describes a method ofrecovering face fiber from a carpet employing numerous steps ofshredding and subjecting it to impact forces to reduce particle size,screen separating and washing the particles, followed by separation inwater in a hydrocyclone. The washing operation optionally includesadditives to improve the wetting and separation of the particles, suchas sodium hydroxide and nonionic surfactant.

Another method to recycle carpet is to dissolve the carpet fiber itselffrom the remaining components. For example, U.S. Pat. No. 5,840,773describes a method of extracting nylon from carpet waste by dissolvingit in an alcohol-water agent. This method disadvantageously uses largequantities of organic solvent. In a further example, U.S. Pat. No.5,889,142 describes a method of extracting nylon from carpet waste bydissolving it in a caprolactam-water mixture. This method also requireslarge quantities of organic solvent.

In still a further example, U.S. Pat. No. 5,932,724 describes a methodof depolymerizing multi-component waste material which is fed to areactor as an extruded melt and contacted with superheated steam at hightemperature and pressure to provide caprolactam which can be purifiedand polymerized. Lastly, U.S. Pat. No. 5,916,410 describes thedifficulty of recycling carpet fibers and describes a process involvingthe use of an organic softener.

Accordingly, there is a need to provide improved methods and systems forrecycling one or more component parts of carpet. Further, there is aneed to provide improved carpet recycling methods and systems that canyield reclaimed materials suitable for use in the manufacture of secondgeneration carpets. Still further, there is a need for the manufactureof carpet structures comprising one or more materials that have beenreclaimed from a post consumer carpet.

SUMMARY OF THE INVENTION

The present invention is based, in part, upon the discovery of a novelmethod for reclaiming one or more polymeric components from carpet. Thecarpet to be recycled can be any carpet. In one aspect, and withoutlimitation, the carpet can be a post or pre consumer carpet,manufacturing remnants, quality control failures, and the like. Themethod generally comprises subjecting post consumer carpet comprising atleast one polymer based component to a terpene containing solventsystem. The polymer component within the post consumer carpet can atleast substantially dissolves in the terpene containing solvent system.After dissolution of the polymer, any non soluble component materialscan be removed from the solvent system, followed by the separation ofthe solvent system from the dissolved polymer component(s). Inembodiments of the invention, the separation of the dissolved polymercomponents can be effected by the extraction of the terpene solvent.After extraction of the terpene solvent is at least substantiallycomplete, a composition remains that comprised the initially dissolvedpolymer material to be reclaimed. This resulting composition can befurther processed in order to render a polymer containing compositionsuitable for use in the manufacture of a second generation carpet,wherein one or more components of the second generation carpet comprisesthe polymer containing composition reclaimed by the process assummarized above.

In another broad aspect, the present invention provides a carpetcomprising a plurality of fibers, a primary backing material having aface and a back side, an optional pre-coat material, an adhesive backingmaterial and an optional secondary backing material, wherein theplurality of fibers are attached to the primary backing material andprotrude from the face of the primary backing material and exposed onthe back side of the primary backing material. In one aspect, theoptional pre-coat layer is applied to the backside of the primarybacking layer, followed by the adhesive backing material being disposedadjacent to the pre-coat layer. Alternatively, if the pre-coat layer isnot present, the adhesive backing material can be disposed on the backside of the primary backing material. According to these aspects, theoptional secondary backing material can be applied adjacent to theadhesive backing material. According to this broad aspect of theinvention, any one or more components of the carpet structure describedabove can comprise a reclaimed polymer composition as described above.In one exemplary aspect, the adhesive backing material comprises areclaimed polymer composition as described above. Still further, themanufactured carpet structure can be a broadloom carpet, a carpet tile,or even an area rug.

In still another broad aspect, the present invention also provides amethod of making a carpet comprising one or more reclaimed polymercompositions as summarized above. The manufactured carpet comprises aface surface comprising yarn, a primary backing material, an adhesivebacking material. As noted above, the carpet can optionally comprise apre-coat layer disposed between the backside of the primary backing andthe adhesive material. Further, the carpet can also optional comprise asecondary backing material wherein the primary backing material has aback surface opposite the face surface of the carpet. According toaspects of the method, the yarn is attached to the primary backingmaterial, the adhesive backing material is applied to the back surfaceof the primary backing material and the optional secondary backingmaterial is applied onto the adhesive backing material. In an exemplaryaspect, the adhesive backing layer comprises a reclaimed polymercomposition as summarized above.

Additional embodiments of the invention will be set forth, in part, inthe detailed description, figures, and claims which follow, and in partwill be derived from the detailed description, or can be learned bypractice of the invention. It is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory only and are not restrictive of the inventionas disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of an exemplary recycling systemand method according to one aspect of the present invention.

FIG. 2 a, FIG. 2 b, and FIG. 2 c are schematic illustrations of anexemplary multiple vessel counter flow solvent dissolution system of thepresent invention.

FIG. 3 is an illustration of an exemplary tufted carpet.

FIG. 4 is a schematic representation of an exemplary extrusion coatingline according to one aspect of the invention.

FIG. 5 is a schematic representation of an exemplary extrusion coatingline according to an aspect of the invention.

FIG. 6 is a schematic representation of an exemplary tufted carpet tileaccording to one aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention can be understood more readily by reference to thefollowing detailed description, examples, drawings, and claims, andtheir previous and following description. However, before the presentdevices, systems, and/or methods are disclosed and described, it is tobe understood that this invention is not limited to the specificdevices, systems, and/or methods disclosed unless otherwise specified,as such can, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting.

The following description of the invention is provided as an enablingteaching of the invention in its best, currently known embodiment. Tothis end, those skilled in the relevant art will recognize andappreciate that many changes can be made to the various aspects of theinvention described herein, while still obtaining the beneficial resultsof the present invention. It will also be apparent that some of thedesired benefits of the present invention can be obtained by selectingsome of the features of the present invention without utilizing otherfeatures. Accordingly, those who work in the art will recognize thatmany modifications and adaptations to the present invention are possibleand can even be desirable in certain circumstances and are a part of thepresent invention. Thus, the following description is provided asillustrative of the principles of the present invention and not inlimitation thereof.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to a “surface” includes aspects having two or moresuch surfaces unless the context clearly indicates otherwise.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance may or may not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

The term “intimate contact” refers to the mechanical interaction betweenthe back surface of the primary backing material and the adhesivebacking material.

The term “substantial encapsulation” refers to the adhesive backingmaterial significantly surrounding the yarn or fiber bundles at or inimmediate proximity to the interface between the back surface of theprimary backing material and the adhesive backing material.

The term “substantial consolidation” refers to the overall integrity anddimensional stability of the carpet that is achieved by substantiallyencapsulating the yarn or fiber bundles and intimately contacting theback surface of the primary backing material with the adhesive backingmaterial. In one aspect, a substantially consolidated carpet possessesgood component cohesiveness and good delamination resistance withrespect to the various carpet components.

The term “integral fusing” is used herein in the same sense as known inthe art and refers to heat bonding of carpet components using atemperature above the melting point of the adhesive backing material. Inthis aspect, integral fusing occurs when the adhesive backing materialcomprises the same polymer as either the fibers or primary backingmaterial or both. However, integral fusing does not occur when theadhesive backing material comprises a different polymer than the fibersand primary backing material. In a further aspect, by the term “samepolymer,” it is meant that the monomer units of the polymers are of thesame chemistry, although their molecular or morphological attributes maydiffer. Conversely, by the term “different polymer,” it is meant that,irrespective of any molecular or morphological differences, the monomerunits of the polymers are of different chemistries. Thus, in accordancewith the various definitions of the present invention, a polypropyleneprimary backing material and a polyethylene adhesive backing materialwould not integrally fuse because these carpet components are ofdifferent chemistries.

The term “carpet component” is used herein to refer separately to carpetfiber bundles, a primary backing material, an optional pre-coat layer,an adhesive backing material, an optional reinforcing layer, and anoptional secondary backing material.

The term “extrusion coating” is used herein in its conventional sense torefer to an extrusion technique wherein a polymer composition usually inpellet-form is heated in an extruder to a temperature elevated above itsmelt temperature and then forced through a slot die to form asemi-molten or molten polymer sheet. The semi-molten or molten polymersheet is continuously drawn down onto a continuously fed greige good tocoat the backside of the greige good with the polymer composition. Itshould also be understood that, as used herein, extrusion coating is notlimited to applying a coating to greige good but, rather, can be used toapply a composition to any desired component of a carpet construction,including for example, primary backing and/or secondary backing.

In one aspect, the term “lamination technique” is used herein in itsconventional sense refer to applying adhesive backing materials togreige goods by first forming the adhesive backing material as asolidified or substantially solidified film or sheet and thereafter, ina separate processing step, reheating or elevating the temperature ofthe film or sheet before applying it to the back surface of the primarybacking material.

The term “heat content” is used herein to refer to the mathematicalproduct of the heat capacity and specific gravity of a filler. Fillerscharacterized as having high heat content are used in specificembodiments of the present invention to extend the solidification ormolten time of adhesive backing materials. The Handbook for ChemicalTechnicians, Howard J. Strauss and Milton Kaufmann, McGraw Hill BookCompany, 1976, Sections 14 and 2-1, the disclosure of which isincorporated herein by reference, provides information on the heatcapacity and specific gravity of select mineral fillers. The fillerssuitable for use in the present invention do not change their physicalstate (i.e., remain a solid material) over the extrusion coatingprocessing temperature ranges of the present invention. Exemplarypreferred high heat content fillers possess a combination of a highspecific gravity and a high heat capacity.

The term “implosion agent” is used herein to refer to the use ofconventional blowing agents or other compounds which out-gas or causeout-gassing when activated by heat, usually at some particularactivation temperature. In the present invention, implosion agents canbe used to implode or force adhesive backing material into the freespace of yarn or fiber bundles.

The term “processing material” is used herein to refer to substancessuch as spin finishing waxes, equipment oils, sizing agents and thelike, which can interfere with the adhesive or physical interfacialinteractions of adhesive backing materials. Optionally, at least some ofthe processing materials can be removed or displaced by a scouring orwashing technique of the present invention whereby improved mechanicalbonding is accomplished.

The terms “polypropylene carpet” and “polypropylene greige goods” areused herein to mean a carpet or greige goods substantially comprised ofpolypropylene fibers, irrespective of whether the primary backingmaterial for the carpet or greige good is comprised of polypropylene orsome other material.

The terms “nylon carpet” and “nylon greige goods” are used herein tomean a carpet or greige goods substantially comprised of nylon fibers,irrespective of whether the primary backing material for the carpet orgreige good is comprised of nylon or some other material.

The term “linear” as used to describe ethylene polymers is used hereinto mean the polymer backbone of the ethylene polymer lacks measurable ordemonstrable long chain branches, e.g., the polymer is substituted withan average of less than 0.01 long branch/1000 carbons.

As used herein, the term “copolymer” refers to a polymer formed from twoor more different repeating units (monomer residues). By way of exampleand without limitation, a copolymer can be an alternating copolymer, arandom copolymer, a block copolymer, or a graft copolymer.

The term “homogeneous ethylene polymer” as used to describe ethylenepolymers is used in the conventional sense in accordance with theoriginal disclosure by Elston in U.S. Pat. No. 3,645,992, the disclosureof which is incorporated herein by reference, to refer to an ethylenepolymer in which the co-monomer is randomly distributed within a givenpolymer molecule and wherein substantially all of the polymer moleculeshave substantially the same ethylene to co-monomer molar ratio. Asdefined herein, both substantially linear ethylene polymers andhomogeneously branched linear ethylene are homogeneous ethylenepolymers.

Homogeneously branched ethylene polymers are homogeneous ethylenepolymers that possess short chain branches and that are characterized bya relatively high short chain branching distribution index (SCBDI) orrelatively high composition distribution branching index (CDBI). Thatis, the ethylene polymer has a SCBDI or CDBI greater than or equal to 50percent, preferably greater than or equal to 70 percent, more preferablygreater than or equal to 90 percent and essentially lack a measurablehigh density (crystalline) polymer fraction.

The SCBDI or CDBI is defined as the weight percent of the polymermolecules having a co-monomer content within 50 percent of the mediantotal molar co-monomer content and represents a comparison of theco-monomer distribution in the polymer to the co-monomer distributionexpected for a Bernoullian distribution. The SCBDI or CDBI ofpolyolefins can be conveniently calculated from data obtained fromtechniques known in the art, such as, for example, temperature risingelution fractionation (abbreviated herein as “TREF”) as described, forexample, by Wild et al., Journal of Polymer Science, Poly. Phys. Ed.,Vol. 20, p. 441 (1982), L. D. Cady, “The Role of Comonomer Type andDistribution in LLDPE Product Performance,” SPE Regional TechnicalConference, Quaker Square Hilton, Akron, Ohio, October 1-2, pp. 107-119(1985), or in U.S. Pat. Nos. 4,798,081 and 5,008,204, the disclosures ofall of which are incorporated herein by reference. However, thepreferred TREF technique does not include purge quantities in SCBDI orCDBI calculations. More preferably, the co-monomer distribution of thepolymer and SCBDI or CDBI is determined using ¹³C NMR analysis inaccordance with techniques described, for example, in U.S. Pat. No.5,292,845 and by J. C. Randall in Rev. Macromol. Chem. Phys., C29, pp.201-317, the disclosures of which are incorporated herein by reference.

The terms “homogeneously branched linear ethylene polymer” and“homogeneously branched linear ethylene/α-olefin polymer” means that theolefin polymer has a homogeneous or narrow short branching distribution(i.e., the polymer has a relatively high SCBDI or CDBI) but does nothave long chain branching. That is, the linear ethylene polymer is ahomogeneous ethylene polymer characterized by an absence of long chainbranching. Such polymers can be made using polymerization processes(e.g., as described by Elston in U.S. Pat. No. 3,645,992) which providea uniform short chain branching distribution (i.e., homogeneouslybranched). In his polymerization process, Elston uses soluble vanadiumcatalyst systems to make such polymers, however others, such as MitsuiPetrochemical Industries and Exxon Chemical Company, have reportedlyused so-called single site catalyst systems to make polymers having ahomogeneous structure similar to polymer described by Elston. Further,U.S. Pat. No. 4,937,299 to Ewen et al. and U.S. Pat. No. 5,218,071 toTsutsui et al., the disclosures of which are incorporated herein byreference, disclose the use of metallocene catalysts for the preparationof homogeneously branched linear ethylene polymers. Homogeneouslybranched linear ethylene polymers are typically characterized as havinga molecular weight distribution, M_(w)/M_(n), of less than 3, preferablyless than 2.8, more preferably less than 2.3.

The terms “homogeneous linearly branched ethylene polymer” or“homogeneously branched linear ethylene/α-olefin polymer” do not referto high pressure branched polyethylene which is known to those skilledin the art to have numerous long chain branches. In one aspect, the term“homogeneous linear ethylene polymer” generically refers to both linearethylene homopolymers and to linear ethylene/α-olefin interpolymers. Forexample, a linear ethylene/α-olefin interpolymer possess short chainbranching and n the α-olefin is typically at least one C₃-C₂₀ α-olefin(e.g., propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and1-octene).

In a further aspect, when used in reference to an ethylene homopolymer(i.e., a high density ethylene polymer not containing any comonomer andthus no short chain branches), the term “homogeneous ethylene polymer”or “homogeneous linear ethylene polymer” means the polymer was exemplarymade using a homogeneous catalyst system such as, for example, thatdescribed Elston or Ewen or those described by Canich in U.S. Pat. Nos.5,026,798 and 5,055,438, or by Stevens et al. in U.S. Pat. No.5,064,802, the disclosures of all three of which are incorporated hereinby reference.

In one aspect, the term “substantially linear ethylene polymer” is usedherein to refer to homogeneously branched ethylene polymers that havelong chain branching. The term does not refer to heterogeneously orhomogeneously branched ethylene polymers that have a linear polymerbackbone. For substantially linear ethylene polymers, the long chainbranches have the same comonomer distribution as the polymer backbone,and the long chain branches can be as long as about the same length asthe length of the polymer backbone to which they are attached. Thepolymer backbone of substantially linear ethylene polymers issubstituted with about 0.01 long chain branches/1000 carbons to about 3long chain branches/1000 carbons, more preferably from about 0.01 longchain branches/1000 carbons to about 1 long chain branches/1000 carbons,and especially from about 0.05 long chain branches/1000 carbons to about1 long chain branches/1000 carbons.

In a further aspect, long chain branching is defined herein as a chainlength of at least 6 carbons, above which the length cannot bedistinguished using ¹³C nuclear magnetic resonance spectroscopy. Thepresence of long chain branching can be determined in ethylenehomopolymers by using ¹³C nuclear magnetic resonance (NMR) spectroscopyand is quantified using the method described by Randall (Rev. Macromol.Chem. Phys., C29, V. 2&3, p. 285-297), the disclosure of which isincorporated herein by reference.

Although current ¹³C nuclear magnetic resonance spectroscopy cannotdetermine the length of a long chain branch in excess of six carbonatoms, there are other known techniques useful for determining thepresence of long chain branches in ethylene polymers, includingethylene/1-octene interpolymers. Two such exemplary methods are gelpermeation chromatography coupled with a low angle laser lightscattering detector (GPC-LALLS) and gel permeation chromatographycoupled with a differential viscometer detector (GPC-DV). The use ofthese techniques for long chain branch detection and the underlyingtheories have been well documented in the literature. See, e.g., Zimm,G. H. and Stockmayer, W. H., J. Chem. Phys., 17, 1301 (1949) and Rudin,A., Modem Methods of Polymer Characterization, John Wiley & Sons, NewYork (1991) pp. 103-112, the disclosures of which are incorporatedherein by reference.

In a further aspect, substantially linear ethylene polymers arehomogeneously branched ethylene polymers and are disclosed in U.S. Pat.No. 5,272,236 and U.S. Pat. No. 5,278,272, the disclosures of which areincorporated herein by reference. Homogeneously branched substantiallylinear ethylene polymers are available from The Dow Chemical Company ofMidland, Mich. as AFFINITY™ polyolefin plastomers and from Dupont DowElastomers JV as ENGAGE™ polyolefin elastomers. Homogeneously branchedsubstantially linear ethylene polymers can be prepared via the solution,slurry, or gas phase polymerization of ethylene and one or more optionalα-olefin comonomers in the presence of a constrained geometry catalyst,such as the method disclosed in European Patent Application 416,815-A,the disclosure of which is incorporated herein by reference. Preferably,a solution polymerization process is used to manufacture thesubstantially linear ethylene polymer used in the present invention.

The terms “heterogeneous” and “heterogeneously branched” mean that theethylene polymer can be characterized as a mixture of interpolymermolecules having various ethylene to comonomer molar ratios.Heterogeneously branched ethylene polymers are characterized as having ashort chain branching distribution index (SCBDI) less than about 30percent. Heterogeneously branched linear ethylene polymers are availablefrom The Dow Chemical Company as DOWLEX™ linear low density polyethyleneand as ATTANE™ ultra-low density polyethylene resins. Heterogeneouslybranched linear ethylene polymers can be prepared via the solution,slurry or gas phase polymerization of ethylene and one or more optionalalpha-olefin comonomers in the presence of a Ziegler Natta catalyst, byprocesses such as are disclosed in U.S. Pat. No. 4,076,698 to Andersonet al., the disclosure of which is incorporated herein by reference.Heterogeneously branched ethylene polymers are typically characterizedas having molecular weight distributions, M_(w)/M_(n), in the range offrom 3.5 to 4.1 and, as such, are distinct from substantially linearethylene polymers and homogeneously branched linear ethylene polymers inregards to both compositional short chain branching distribution andmolecular weight distribution.

The substantially linear ethylene polymers useful in this inventionsurprisingly have excellent processability, even though they haverelatively narrow molecular weight distributions (MWDs). In this aspect,the melt flow ratio (I₁₀/I₂) of the substantially linear ethylenepolymers can be varied essentially independently of the polydispersityindex (i.e., molecular weight distribution (M_(w)/M_(n))). This iscontrasted with conventional heterogeneously branched linearpolyethylene resins which have theological properties such that as thepolydispersity index increases, the I₁₀/I₂ value also increases. Therheological properties of substantially linear ethylene polymers alsodiffer from homogeneously branched linear ethylene polymers which haverelatively low, essentially fixed I₁₀/I₂ ratios.

References in the specification and concluding claims to parts by weightof a particular element or component in a composition or article,denotes the weight relationship between the element or component and anyother elements or components in the composition or article for which apart by weight is expressed. Thus, in a composition or a selectedportion of a composition containing 2 parts by weight of component X and5 parts by weight component Y, X and Y are present at a weight ratio of2:5, and are present in such ratio regardless of whether additionalcomponents are contained in the composition.

A weight percent of a component, unless specifically stated to thecontrary, is based on the total weight of the formulation or compositionin which the component is included.

As used herein, and unless the context clearly indicates otherwise, theterm carpet is used to generically include broadloom carpet, carpettiles, and even area rugs. To that “broadloom carpet” means a broadloomtextile flooring product manufactured for and intended to be used inroll form. “Carpet tile” denotes a modular floor covering,conventionally in 18″×18,″ 24″×24″ or 36″×36″ squares, but other sizesand shapes are also within the scope of the present invention.

The present invention may be understood more readily by reference to thefollowing detailed description of preferred embodiments of the inventionand the examples included therein and to the Figures and their previousand following description.

As summarized above, in one broad aspect, the present invention providesa carpet recycling system and method for reclaiming one or more polymersfrom a manufactured carpet structure, such as a post consumer carpetstructure. The recycling system and method can be used to reclaim anypolymeric material that is soluble in a terpene containing solventsystem. Exemplary polymers that can be reclaimed and that are commonlyfound in manufactured carpet structures include, polyethylene polymerssuch as a low density polyethylene (LDPE), heterogeneously branchedlinear low density polyethylene (LLDPE), high density polyethylene(HDPE), heterogeneously branched ultra low density polyethylene (ULDPE),heterogeneously branched very low density polyethylene (VLDPE),heterogeneously branched linear low density polyethylene (LLDPE),heterogeneously branched linear very low density polyethylene (VLLDPE),a copolymer of ethylene and alpha olefin, polypropylene, a copolymer ofpropylene and alpha olefin, a copolymer of propylene and ethylene,ethylene vinyl acetate copolymer (EVA), ethylene methyl acrylatecopolymer (EMA), grafted polyethylene polymers (e.g., a maleic anhydrideextrusion grafted heterogeneously branched linear low polyethylene or amaleic anhydride extrusion grafted homogeneously branched ultra lowdensity polyethylene), ethylene acrylic acid copolymer, ethylene ethylacrylate copolymer, polystyrene, polyolefin, polybutylene,polycarbonate, ethylene propylene polymers, ethylene styrene polymers,and styrene block copolymers.

In an exemplary and non-limiting aspect, the methods and systems of thepresent invention can be used to reclaim homogeneously branched ethylenepolymers from a post consumer carpet composition. Exemplaryhomogeneously branched ethylene polymers that can be reclaimed includethose used as adhesive backing materials in the carpets structuresdescribed in U.S. patent application Ser. No. 11/193,277, filed Jul. 29,2005, the entire disclosure of which is incorporated herein by referencefor all purposes. In addition to the reclamation of these polymercomponents, as will be described in more detail below, the methods andsystems of the present invention can also enable the reclamation of oneor more non-terpene soluble component parts of a carpet composition,including for example, nylon yarn fibers, inorganic flame retardants,additives, and fillers.

The manufactured carpet structure comprising the polymer to be reclaimedcan be any desired carpet structure, including without limitation,tufted carpet, needle-punched carpet, and even hand woven carpet.Additionally, the system and method can be used in connection withbroadloom carpets, carpet tiles, and even area rugs, so long as thecarpet structure comprises at least one polymer material soluble in aterpene based solvent system. In one aspect, the carpet structure to berecycled comprises fiber bundles, a primary backing material, anoptional pre-coat layer, an adhesive backing material, an optionalreinforcing layer, and an optional secondary backing material. To thatend, a polymer material to be reclaimed can be present in any one ormore of those component parts. For example, in one aspect, the fiberbundles can be comprised of polypropylene fiber bundles. According tothis aspect, the polypropylene in fiber bundles can be reclaimed by themethods and systems described herein. In another aspect, however, thefiber bundles may comprise a nylon material that is not soluble in aterpene containing solution. According to this aspect, the polymer to bereclaimed can be in one or more other component parts of the carpetstructure. For example, one or more polymer components as describedabove can be present in the adhesive backing material or even theoptional secondary backing material. Accordingly, it should beunderstood that the carpet to be used as a feedstock in the methods andsystems of the present invention are not limited to any particular form,structure, or materials, provided the carpet comprises at least onepolymer that is soluble in a terpene solvent system. Further, it iscontemplated that the carpet to be recycled can be any carpet. In oneaspect, and without limitation, the carpet can be a post or pre consumercarpet, manufacturing remnants, quality control failures, and the like.

FIG. 1 schematically illustrates an exemplary recycling method andsystem 100 according to one aspect of the present invention. As shown, apost consumer carpet feedstock 110 is provided. The carpet feedstock 110can again be any desired carpet structure comprising at least onepolymer composition as described herein. As is commonly found inconnection with post consumer carpet, extraneous materials that can bedetrimental to the efficiency of the recycling process may be present inthe post consumer carpet. Exemplary extraneous materials can includemetallic materials such as staples, metal strips, nails, brads, or eventools that were used during the removal of the carpet from the locationof its initial installation. Accordingly, the system and method canoptionally comprise step 120 wherein any extraneous materials are firstremoved from the post consumer carpet. Once the extraneous materials areremoved (if at all) the post consumer carpet can then be sent to a sizereduction station 130. The size reduction can increase the surface areaof the carpet that can contact the solvent system and thus facilitatethe dissolution of polymer into the terpene solvent system. To that end,the size reduction can be accomplished by any conventional industrialshredder, guillotine, grinder, and the like. In one aspect, preferredsize reduction equipment includes a Herbold Type SMS 60/100/G3/2granulator. While any desired size reduction can also be used, in apreferred aspect the carpet is reduced to a plurality of chunks orpieces having an average length and/or width in the range of from 0.5inches up to 4 inches.

Once the feedstock carpet has been reduced to appropriately sizedpieces, the feedstock can optionally be pre-washed in a washing station140 to remove any impurities such as dirt, sand, oil, inorganic waste,or organic waste that may be present in the post consumer carpet. Theoptional pre-wash of the sized reduced carpet pieces can comprises asolvent wash utilizing, for example, water, acetone, or even an organicsolvent.

After the optional pre-washing, the carpet feedstock is introduced intoa solvent system 150 comprising a terpene. Once introduced into thesolvent system, any terpene soluble polymeric material as describedherein will dissolve in the terpene solvent. If desired, the solventsystem can be heated above ambient temperature to facilitate thedissolution of polymer into the solvent. For example, according toaspects of the invention it can be desirable to heat the solvent to nearbut still below the boiling point of the terpene solvent system.Additionally, in still other aspects, the solvent system can bemaintained under elevated pressures. As one of skill in the art willappreciate, a pressurized vessel can be used to maintain the solventsystem under increased pressure. By increasing the pressure, the solventsystem can be heated to even higher temperatures without reaching theboiling point of the pressurized solvent, further facilitating thedissolution of polymer in the solvent system.

The dissolution step can comprise contacting the carpet with the solventsystem in a single vessel maintained under desired temperature andpressure conditions as described above, for a sufficient period of timeto at least substantially dissolve any terpene soluble polymers presentin the carpet. However, in an alternative aspect, the dissolution stepcan comprise a plurality of sequential dissolution vessels in which aninitial carpet feedstock is sequentially introduced into the pluralityof dissolution vessels. The use of a plurality of vessels can maximizethe concentration of dissolved polymer that can be achieved in a givenvessel prior to devolatilization as described below. With reference toFIG. 2, an exemplary dissolution system 200 comprised of threesequential counter flow tanks is illustrated. In FIG. 2 a, carpet 205 isfirst introduced into vessel 1 initially comprised of pure solvent,wherein a first portion of terpene soluble polymeric materials withinthe carpet begin to dissolve into the solvent system. Due to varyingrates of dissolution associated with different materials that may bepresent in the carpet, the efficiency of vessel 1 in dissolvingsubstantially all of the terpene soluble polymer may significantlydecrease before the solvent reaches a maximum concentration ofsolubilized polymer or before substantially all of the terpene solublepolymer has been dissolved. Accordingly, after a first portion of thepolymer has dissolved, the remaining carpet 205′, including non solublematerial and additional terpene soluble polymer can be removed fromvessel 1 and introduced into vessel 2, initially containing puresolvent. Once in vessel 2, a second portion of terpene soluble polymerwill dissolve in the solvent system. However, again due to varying ratesof dissolution associated with different materials that may be presentin the carpet, the efficiency of vessel 2 in dissolving substantiallyall of the remaining terpene soluble polymer may significantly decreasebefore the solvent reaches a maximum concentration of solubilizedpolymer. Accordingly, after a second portion of the polymer hasdissolved in vessel 2, the remaining carpet 205″, including non solublematerial and additional terpene soluble polymer can be removed fromvessel 2 and subsequently introduced into vessel 3, again initiallycontaining pure solvent. This process can be repeated until the maximumconcentration of dissolved polymer has been reached in vessel 1, atwhich time vessel 1 can be taken off line for subsequentdevolatilization and reclamation of the dissolved polymer.

As shown in FIG. 2 b, once vessel 1 has been removed, vessels 2 and 3can each be advanced forward and a new vessel 4 containing pure solventcan be introduced into the system. The sequential dissolution process asdescribed above can then be repeated until a maximum concentration ofdissolved polymer is reached in vessel 2, at which time vessel 2 canthen be taken off line for subsequent devolatilization and reclamationof the dissolved polymer. As shown, in FIG. 2 c, once vessel 2 isremoved, vessel three and 4 can each be advanced forward and new vessel5 can be introduced. It should be understood that although theexemplified counter flow process is shown comprising three dissolutionvessels, the process can utilize any desired number of devolatilizationvessels and is not limited to the exemplified aspect.

The terpene solvent system 150 comprises at least one terpene having thegeneric structure:

wherein each “

” connotes an optional bond; at least two of the optional bonds arepresent; R¹, R^(1′), and R⁵ are independently selected from alkyl andcarboxyl; R³, R⁴, and R⁷ are independently selected from hydrogen,hydroxyl, carbonyl, halogen, alkyl, alkoxyl, carboxyl, and acyl; and R⁶is selected from hydrogen, hydroxyl, or oxygen. In an exemplary aspect,the terpene solvent system can comprise a terpene as set forth above,further wherein: R¹ and R⁵ are methyl; the optional bond between C1 andC2 is present and R^(1′) is methylene; the optional bond between C1 andC2 is present; and wherein R³, R⁴, and R⁷ are hydrogen. In anotherexemplary aspect, the terpene can have the general structure set forthabove wherein the optional bonds between C5 and C6 and between C6 and R⁶are absent, and wherein C6 has an S configuration.

In exemplary aspects, the terpene can be dipentene (racemic limonene).Alternatively, the terpene can be nonracemic1-methyl-4-prop-1-en-2-yl-cyclohexene (either R or S limonene). Stillfurther, the terpene can be the (S)-enantiomer (unnatural limonene). Inanother aspect, the terpene is2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enone.

In an alternative aspect, the at least one terpene can be D-Limonene,having the structure:

In an alternative aspect, the at least one terpene can be carveol,having the structure:

Still further, the at least one terpene can have the structure:

In still another aspect, the at least one terpene can have thestructure:

In another aspect, the at least one terpene can be pinene. To that end,in one exemplary aspect the pinene can be an alpha pinene having thestructure:

Alternatively, the pinene can be a beta pinene having the structure

It is also contemplated that, in certain aspects, solvents known tothose of skill in the art having a similar solubility parameter, asimilar dielectric constant, a similar miscibility, a similarhydrophilicity, and similar hydrophobicity, a similar density, a similarboiling point, and/or a similar chemical structure can be substitutedfor, or combined with, the disclosed solvents.

In addition to the terpene, the solvent system can optionally furthercomprise at least one secondary solvent. For example, an added secondaryor co-solvent can be used as a separating agent to facilitate separationof a dissolved polymer from the terpene containing solution. In oneaspect, the secondary solvent can comprise one or more hydrocarbonsselected from, for example and not meant to be limiting, pentane,hexane, cyclohexane, heptane, and octane; one or more alcohols selectedfrom, for example and not meant to be limiting, methanol, ethanol,propanol, butanol, pentanol, tertiary butanol, and isopropyl; one ormore ketones selected from, for example and not meant to be limiting,acetone, butanone, cyclohexanone; or one or more hydrocarbons; or amixture thereof. Accordingly, the at least one terpene can be present inthe solvent system in any desired amount in the range of from about 25%to about 100% by volume and the at least one secondary solvent can bepresent at from about 0% to about 25% by volume. Still further, inanother aspect, the at least one terpene can be present at from about50% to about 100% by volume and the at least one secondary solvent ispresent at from about 0% to about 50% by volume. In still anotherexemplary aspect, the at least one terpene can be present in an amountof from about 75% to about 100% by volume and the at least one secondarysolvent can be present in an amount of from about 0% to about 25% byvolume.

It will be appreciated that the optimum weight ratio of solvent tomaterial being dissolved will vary depending, in part, upon theparticular solvent system being used and/or the composition of theparticular carpet structure being dissolved. However, in certainexemplary aspects and without limitation, the weight ratio of terpenesolvent to terpene soluble polymer present within the carpet material,based upon total weight percent, can be approximately 1:1, 5:1, 7:1,10:1, 15:1, 20:1, 25:1, or even up to 50:1. Further, as one of skill inthe art will appreciate, it can be desirable to minimize the amount ofsolvent used as this will reduce the amount of solvent to be extractedfrom the solution during the devolatilization process.

After dissolution of the polymer is at least substantially complete, theterpene solution comprising the dissolved polymer can then be conveyedto a separation station 160 whereby any undissolved components can beseparated from the solvent system. For example, an initial carpetfeedstock to be recycled can include, for example and not meant to belimiting, inorganic materials, such as fillers and flame retardants, andpolymeric materials such as nylon faces fibers and other polymers thatare not be soluble in the terpene solvent system. These materials 165can be mechanically removed from the solution during this subsequentseparation step 160. Any conventional method for removal of solids froma solution can be used. For example, non-soluble yarns and or fiberbundles can be separated by conventional filtration using for example astrainer basket or a filter bag. Non-soluble particulate solids, such asinorganic fillers and flame retardants can be recovered using techniquessuch as centrifugal separation, membrane filtration, vacuum beltfiltration, candle tube filtration, and vibratory shear enhancedfiltration process (VSEP). In an exemplary aspect, preferred equipmentfor separation of materials 165 includes the PANNEVIS RT-GT HGD VacuumBelt Filter from Larox, Inc. Further, once separated, these non-solublematerials can be further processed for subsequent use in secondgeneration carpet materials. Subsequent processing can include forexample, step 167 for drying the separated non-soluble materials of anyresidual solvent. During this drying step 167, the residual solvent canbe collected for reuse in the recycling system described herein.

Following the separation of any non-soluble component materials 165, theterpene solvent system comprising the dissolved polymer is subjected todevolatilization 170. The devolatilization can utilize any conventionalmeans for separating the terpene solvent from the dissolved polymercompositions, including, for example and without limitation,distillation, vacuum pressure, a flash tank process, vented extruder, oreven a wiped film evaporator. In an exemplary aspect, the terpenesolvent can be extracted from the solution by distillation, resulting inthe at least substantial separation of the terpene solvent from theinitially dissolved polymer material. During the separation, extractedsolvent system 175 can be collected for subsequent use as solvent in therecycling systems and methods described herein. In an exemplary aspect,preferred equipment for extracting terpene solvent includes the use ofthe 7 liter CSTR from LIST USA, Inc.

Following the initial devolatilization step 170, it should be understoodthat the remaining reclaimed polymer composition can, depending on thecomposition of the post consumer carpet, comprise a blend of two or moresoluble polymeric materials. Further, the initially reclaimed polymermaterial can also comprise one or more polymeric additives or eventcontaminants that were present in the original carpet pieces. It is evencontemplated that the reclaimed polymer composition will still compriseresidual unextracted terpene solvent. Accordingly, the reclaimed polymercomposition can optionally be further processed to remove any one ormore of these portions of the polymer composition. For example, in theexemplary aspect shown in FIG. 1, the reclaimed polymer composition canbe conveyed to an optional second or subsequent devolatilization station180 to remove residual solvent. The second or any subsequentdevolatilization step can again use the equipment references above inconnection with the first devolatilization step. Exemplary equipment caninclude the WE series 2″ non intermeshing, counter rotating, vented,54:1 L/D twin screw extruder from NFM Welding Engineers.

In an exemplary aspect, the optional second devolatilization step can,for example, comprising passing the initially reclaimed polymercomposition from the first devolatilization step 170 through a ventedextruder to render reclaimed polymer 190. The reclaimed polymer can befurther processed into any desired form for subsequent use and/orstorage. For example, the reclaimed polymer 190 can be palletized using,for example, a Gala under water pelletizer or a Conair strandpelletizer.

As described in further detail below, the reclaimed polymer 190 can beused in the manufacture of one or more components of a second generationcarpet composition. Still further, any residual terpene solvent 185 thatmay have been present in the initially reclaimed polymer material ofstep 170 can also be collected during the extrusion process andsubsequently reused in further recycling processes. It should also beunderstood that the process as described herein can according to someembodiments be configured for use as a batch wise process.Alternatively, the process as described can also be configured as acontinuous process.

According to aspects of the invention, the reclaimed polymercompositions resulting from the process described herein can exhibitphysical properties that are indicative of their suitability forsubsequent use in the manufacture of second generation carpets. Forexample, in one aspect the reclaimed polymer compositions of the presentinvention exhibit a melt flow rate, as measured according to ASTMD1238-04C, in the range of from 2 g/10 min to 200 g/10 min, includingexemplary ratios of 10 g. 10 min, 25 g/10 min, 50 g/10 min, 75 g/10 min,100 g/10 min, 125 g/10 min, 150 g/10 min, 175 g/10 min, and any valuewithin a range of melt flow rates derived from any two of these values.In still other aspects, the reclaimed polymer compositions can exhibit amelt flow rates, as measured according to ASTM D1238-04C in the range offrom 20 g/10 min to 100 g/10 min, including exemplary melt flow rates of30 g/10 min, 40 g/10 min, 50 g/10 min, 60 g/10 min, 70 g/10 min, 80 g/10min, 90 g/10 min, and any melt flow rates within a range of melt flowrates derived from any two of these values.

In accordance with another broad aspect, the present invention providesa second generation carpet comprising a polymer composition reclaimedfrom the process described above. In a preferred aspect, the secondgeneration carpet can be a tufted broadloom carpet. In an alternativeaspect, the second generation carpet can be a tufted carpet tile. Asillustrated in FIG. 3, an exemplary tufted carpet 300 is shown. Thetufted carpet 300 is a composite structure which includes yarn 320(which is also known as a fiber bundle), a primary backing material 310having a face surface 312 and a back surface 314, an adhesive backingmaterial 330 and, optionally, a secondary backing material 340. To formthe face surface of tufted carpet, the yarn is tufted through theprimary backing material such that the longer length of each stitchextends through the face surface of the primary backing material.

The face of a tufted carpet can generally be made in three ways. First,for loop pile carpet, the yarn loops formed in the tufting process areleft intact. Second, for cut pile carpet, the yam loops are cut, eitherduring tufting or after, to produce a pile of single yarn ends insteadof loops. Third, some carpet styles include both loop and cut pile. Onevariety of this hybrid is referred to as tip-sheared carpet where loopsof differing lengths are tufted followed by shearing the carpet at aheight so as to produce a mix of uncut, partially cut, and completelycut loops. Alternatively, the tufting machine can be configured so as tocut only some of the loops, thereby leaving a pattern of cut and uncutloops. Whether loop, cut, or a hybrid, the yarn on the back side of theprimary backing material comprises tight, unextended loops.

The combination of tufted yarn and a primary backing material withoutthe application of an adhesive backing material or secondary backingmaterial is referred to in the carpet industry as raw tufted carpet orgreige goods. Greige goods become finished tufted carpet with theapplication of an adhesive backing material and an optional secondarybacking material to the back side of the primary backing material.Finished tufted carpet can be prepared as broad-loomed carpet in rollstypically 6 or 12 feet wide. Alternatively, carpet can be prepared ascarpet tiles, which are, for example and without limitation, typically24 inches square in the United States and 50 cm. square elsewhere.

The adhesive backing material is applied to the back face of the primarybacking material to affix the yarn to the primary backing material. Inone aspect, the adhesive backing substantially encapsulates a portion ofthe back stitching of the yarn, penetrates the yarn, and bindsindividual carpet fibers. Properly applied adhesive backing materials donot substantially pass through the primary backing material.

As noted above and shown in FIG. 3, the carpet of the inventionpreferably also includes an optional secondary backing material.Preferably, the secondary backing material is laminated directly to anextruded adhesive backing layer(s) while the extrudate is still moltenafter extrusion coating. It has been found that this technique canimprove the penetration of the extrusion coating into the primarybacking.

Alternatively, the secondary backing material can be laminated in alater step by reheating and/or remelting at least the outermost portionof the extruded layer or by a coextrusion coating technique using atleast two dedicated extruders. Also, the secondary backing material canbe laminated through some other means, such as by interposing a layer ofa polymeric adhesive material between the adhesive backing material andthe secondary backing material. Suitable polymeric adhesive materialsinclude, but are not limited to, ethylene acrylic acid (EAA) copolymers,ionomers and maleic anhydride grafted polyethylene compositions.

The material for the secondary backing material can be a conventionalmaterial such as the woven polypropylene fabric sold by Propex, Inc.under the designation Action Bac®. This material is a leno weave withpolypropylene monofilaments running in one direction and polypropyleneyarn running in the other. A suitable example of such a material is soldby Propex, Inc. under the designation Style 3870. This material has abasis weight of about 2 OSY. In another aspect, the secondary backingmaterial used with the present invention can be a woven polypropylenefabric with monofilaments running in both directions.

Alternatively, the secondary backing material can be a non-woven fabric.Several types are available, including, but not limited to, needlepunched, spun-bond, wet-laid, melt-blown, hydraentangled, and airentangled. In one aspect, it is preferred that the secondary backing ismade from a polyolefin to facilitate recycling. For example, thenon-woven fabric can be spun-bond polypropylene fabric. Typically,spun-bond fabric is made from extruded and air-drawn polymer filamentswhich are laid down together and then point bonded, for example by aheated calendar roll. The basis weight of such a spun-bond secondarybacking can be varied, preferably between 35 and 80 grams/m² (gsm) morepreferably between 60 and 80 gsm. Most preferably, the basis weight is77-83 gsm (e.g., 80 gsm). One factor favoring a higher basis weight forthe spun-bond fabric is that the higher basis weight fabric is lesslikely to be melted when brought into contact with the molten extrudedbacking. In another example, it is preferred to use a needle punchednon-woven secondary backing. An exemplary polypropylene non-woven needlepunched secondary backing material is available from Propex, Inc. underthe designation style number 9001641, having a basis weight of about 3.5OSY.

In still another aspect, the secondary backing can be a woven needlepunched polypropylene fabric such as SoftBac® manufactured by ShawIndustries, Inc. In this exemplary aspect, this material has beenenhanced by having about 1.5 OSY of polypropylene fibers needle punchedonto one side of it and has a total basis weight of about 3.5 OSY. Thisneedle punched fabric is laminated so as to have the polypropylenefibers embedded within the adhesive backing layer. As a result, thestrands of the woven polypropylene fabric exposed. This embodiment hasbeen shown to have improved glue down properties as compared to anembodiment without the needle punched fibers because, without the needlepunched fibers, the strands of the woven polypropylene fabric are atleast partially embedded in the adhesive backing layer. As such, thesurface area for gluing is reduced. It was also noted that the back ofthe carpet made in this embodiment was much less abrasive than thatfound with traditional latex backed carpet. The carpet is also moreflexible than traditional latex backed carpet. Consequently, thisembodiment is preferred for making areas rugs and the like. Still othermaterials can be used for the secondary backing. For example, if anintegral pad is desired, polyurethane foam or other cushion material canbe laminated to the back side of the carpet. Such backings can be usedfor broadloom carpet as well as for carpet tile.

According to an aspect of the present invention, the adhesive backingmaterial of the exemplified tufted carpet structure described above is arecycled adhesive backing composition. At least a portion of therecycled adhesive composition is comprised of one or more reclaimedpolymeric materials that have been reclaimed from post consumer carpetas described above. To that end, the second generation adhesivecompositions of the present invention comprise a polymeric portion and afiller portion. According to some aspects, the polymeric portion of therecycled adhesive composition can be comprised entirely of reclaimedpolymer material. Alternatively, the polymeric portion of the recycledadhesive can be a combination of reclaimed polymer and a virgin ornon-recycled polymer component. Accordingly, the recycled polymerportion of the adhesive composition can be present in any amount in therange of from greater than 0 weight to about 100 weight percent of thepolymer component of the adhesive composition, based on the total weightof the polymer portion of the adhesive composition. For example, thereclaimed polymer can also be present, without limitation, in exemplaryrelative weight percentages of 5 wt %, 10 wt %, 15 wt %, 20 wt %, 25 wt%, 30 wt %, 35 wt %, 40%, 45 wt %, 50%, 55%, 60%, 65%, 70%, 75%, 80%,85%, 90%, and 95%. Still further, the reclaimed polymer portion can bepresent in an amount within any range of from a first percentage to asecond percentage wherein the first and second percentages are selectedfrom any of the above mention weight percentage values.

As one of skill in the art will appreciate, the actual composition ofthe reclaimed polymer material used in the adhesive composition willdepend upon the particular terpene soluble components that were presentin the initial carpet material subjected to the recycling processdescribed above. According to aspects of the invention, the reclaimedpolymer composition can comprise one or more polyolefin polymers. Forexample, the reclaimed polymer composition can comprise a polyethylenepolymer such as a low density polyethylene (LDPE), heterogeneouslybranched linear low density polyethylene (LLDPE), high densitypolyethylene (HDPE), heterogeneously branched ultra low densitypolyethylene (ULDPE), heterogeneously branched very low densitypolyethylene (VLDPE), heterogeneously branched linear low densitypolyethylene (LLDPE), heterogeneously branched linear very low densitypolyethylene (VLLDPE), a copolymer of ethylene and alpha olefin,polypropylene, a copolymer of propylene and alpha olefin, a copolymer ofpropylene and ethylene, ethylene vinyl acetate copolymer (EVA), ethylenemethyl acrylate copolymer (EMA), grafted polyethylene polymers (e.g., amaleic anhydride extrusion grafted heterogeneously branched linear lowpolyethylene or a maleic anhydride extrusion grafted homogeneouslybranched ultra low density polyethylene), ethylene acrylic acidcopolymer, ethylene ethyl acrylate copolymer, polystyrene, polyolefin,polybutylene, polycarbonate, ethylene propylene polymers, ethylenestyrene polymers, and styrene block copolymers. Still further, it shouldbe understood that the recycled polymer portion of the adhesive cancomprise any combination of the aforementioned polymers in any varyingrelative weight percentages.

In addition to the above listed polyethylene polymer, the reclaimedpolymeric composition can also comprise one or more non-polymericmaterials that were present in the first generation carpet to berecycled may also be present in combination with the reclaimedpolyolefin material (again by virtue of having been present in theinitial carpet feedstock being recycled). Therefore, exemplary andnon-limiting non-polyolefin compositions that may be present in therecycled polymer portion of adhesive composition include, withoutlimitation, ethylenically unsaturated carboxylic acids, anhydrides,alkyl esters and half esters, e.g., acrylic acid, methacrylic acid,maleic acid, maleic anhydride, itaconic acid, fumaric acid, crotonicacid and citraconic acid, citraconic anhydride, succinnic acid,succinnic anhydride, methyl hydrogen maleate, and ethyl hydrogenmaleate; esters of ethylenically unsaturated carboxylic acids, e.g.,ethyl acrylate, methyl methacrylate, ethyl methacrylate, methylacrylate, isobutyl acrylate, and methyl fumarate; unsaturated esters ofcarboxylic acids, e.g., vinyl acetate, vinyl propionate, and vinylbenzoate; and ethylenically unsaturated amides and nitriles e.g.,acrylamide, acrylonitrile, methacrylonitrile and fumaronitrile; and (2)one or more ethylenically unsaturated hydrocarbon monomers such asolefin monomers or aliphatic α-olefin monomers or copolymers thereof,e.g., ethylene, propylene, butene-1 and isobutene; conjugated dienes,e.g., butadiene and isoprene; and monovinylidene aromatic carbocyclicmonomers, e.g., styrene, α-methylstyrene, toluene, and t-butylstyrene.

As noted above, the polymeric portion of the adhesive composition cancomprise a blend of recycled polymer composition and one or more virginpolymer compositions. To that end, when present in the polymer portionof the adhesive composition, the virgin polymer portion can be presentin an amount in the range of from about 0 to about 99 weight percent ofthe total polymer portion based on the total weight of the polymercomponents present within the polymer portion of the adhesivecomposition. Further exemplary weight percentages include, withoutlimitation, 5%, 10%, 15 wt %, 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt%, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %, 70%, 75 wt %, 80 wt %,85 wt %, 90 wt % or even 95 wt %. In still another aspect, the virginpolymer component of the adhesive composition can be present in anamount within any range of from a first percentage to a secondpercentage wherein the first and second percentages are selected fromany of the above mention weight percentage values.

When present in the adhesive composition, the virgin polymer componentcan comprise a polyethylene polymer such as a low density polyethylene(LDPE), heterogeneously branched linear low density polyethylene(LLDPE), high density polyethylene (HDPE), heterogeneously branchedultra low density polyethylene (ULDPE), heterogeneously branched verylow density polyethylene (VLDPE), heterogeneously branched linear lowdensity polyethylene (LLDPE), heterogeneously branched linear very lowdensity polyethylene (VLLDPE), a copolymer of ethylene and alpha olefin,polypropylene, a copolymer of propylene and alpha olefin, a copolymer ofpropylene and ethylene, ethylene vinyl acetate copolymer (EVA), ethylenemethyl acrylate copolymer (EMA), grafted polyethylene polymers (e.g., amaleic anhydride extrusion grafted heterogeneously branched linear lowpolyethylene or a maleic anhydride extrusion grafted homogeneouslybranched ultra low density polyethylene), ethylene acrylic acidcopolymer, ethylene ethyl acrylate copolymer, polystyrene, polyolefin,polybutylene, polycarbonate, ethylene propylene polymers, ethylenestyrene polymers, and styrene block copolymers.

In a preferred aspect, the virgin polymer component comprises ahomogeneously branched linear ethylene polymers such as substantiallylinear ethylene polymer. In an exemplary aspect, a preferredsubstantially linear ethylene polymers that can be used in the virginpolymer component include the Affinity® series of polymers availablefrom Dow Chemicals. These preferred exemplary ethylene polymers offerunique advantages for extrusion coated carpet backing applications,especially for commercial and residential carpet markets. For example,they have relatively low solidification temperatures, relatively goodadhesion to polypropylene which can be beneficial when the fiber bundlesare comprised of polypropylene, and lower modulus relative toconventional ethylene polymers such as low density polyethylene (LDPE),heterogeneously branched linear low density polyethylene (LLDPE), highdensity polyethylene (HDPE), and heterogeneously branched ultra lowdensity polyethylene (ULDPE).

In the present invention, during extrusion coating of the backside ofcarpet to apply the adhesive backing material, the adhesive compositionprovides good penetration of carpet yarns (fiber bundles) and alsoallows for good consolidation of the fibers within the yarn. In oneaspect, when used as an adhesive backing for tufted carpets, a tuft bind(or tuft lock) strength of 3.25 pounds (1.5 kg) or more can be achieved,more preferably 5 pounds (2.3 kg) or more, and even most preferably 7.5pounds (3.4 kg) or more. In a further aspect, tuft bind strength can bealso be increased by increasing the molecular weight of the selectedvirgin polymer component present in the adhesive composition. However, ahigher polymer molecular weight selected for improved tuft bind strengthis contra to the requirement of a lower polymer molecular weight whichis generally needed for good yarn penetration and good extrusioncoatability. As such, the properties of the blended recycled and virginpolymer components should be chosen such that a balance is maintainedbetween extrusion coatability and abrasion resistance as well as betweenchemical resistance and carpet flexibility.

In a further aspect, when carpet greige good is backed with an adhesivecomposition comprising the substantially linear ethylene polymers andhomogeneously branched linear ethylene polymers, (whether present as aportion of a virgin polymer, a recycled polymer portion, or acombination thereof) the low flexural modulus of these can offeradvantages in ease of carpet installation and general carpet handling.In this aspect, the substantially linear ethylene polymers, inparticular, show enhanced mechanical adhesion to polypropylene whenemployed as an adhesive backing material, which improves theconsolidation and delamination resistance of the various carpet layersand components, i.e., polypropylene fibers, fiber bundles, the primarybacking material, the adhesive backing material and the secondarybacking material when optionally applied. Consequently, in thisexemplary aspect, exceptionally good abrasion resistance and tuft bindstrength can be obtained. As one skilled in the art will appreciate,good abrasion resistance is important in commercial carpet cleaningoperations as good abrasion resistance generally improves carpetdurability.

Operationally, the use of the preferred substantially linear ethylenepolymers and homogeneously branched linear ethylene polymers as acomponent of the adhesive (whether present as a portion of a virginpolymer, a recycled polymer portion, or a combination thereof) can allowfor the elimination of secondary backing materials and as such canresult in significant manufacturing cost savings. In addition, carpetsadhesively backed with the preferred polymer adhesive can provide asubstantial fluid and particle barrier which enhances the hygienicproperties of carpet.

An exemplary preferred homogeneously branched ethylene polymer that canbe used as a virgin polymer or that can be present in a post consumercarpet to be recycled has a single melting peak in the temperature rangeof between −30° C. and 150° C., as determined using differentialscanning calorimetry. The most preferred homogeneously branched ethylenepolymer for use in the invention is a substantially linear ethylenepolymer characterized as having

-   -   (a) a melt flow ratio, I₁₀/I₂≦5.63,    -   (b) a molecular weight distribution, M_(w)/M_(n), as determined        by gel permeation chromatography and defined by the equation:        i.(M _(w) /M _(n))≦(I ₁₀ /I ₂)−4.63,    -   (c) a gas extrusion rheology such that the critical shear rate        at onset of surface melt fracture for the substantially linear        ethylene polymer is at least 50 percent greater than the        critical shear rate at the onset of surface melt fracture for a        linear ethylene polymer, wherein the linear ethylene polymer has        a homogeneously branched short chain branching distribution and        no long chain branching, and wherein the substantially linear        ethylene polymer and the linear ethylene polymer are        simultaneously ethylene homopolymers or interpolymers of        ethylene and at least one C₃-C₂₀ α-olefin and have the same I₂        and M_(w)/M_(n) and wherein the respective critical shear rates        of the substantially linear ethylene polymer and the linear        ethylene polymer are measured at the same melt temperature using        a gas extrusion rheometer, and    -   (d) a single differential scanning calorimetry, DSC, melting        peak between −30° C. and 150° C.

In one example, the determination of the critical shear rate in regardsto melt fracture as well as other rheology properties such as“rheological processing index” (PI) can be performed using a gasextrusion rheometer (GER). One exemplary gas extrusion rheometer isdescribed by M. Shida, R. N. Shroff and L. V. Cancio in PolymerEngineering Science Vol. 17, No. 11, p. 770 (1977), and in “Rheometersfor Molten Plastics” by John Dealy, published by Van Nostrand ReinholdCo. (1982) on pp. 97-99, the disclosures of both of which areincorporated herein by reference. In one example, the GER experimentsare performed at a temperature of 190° C., at nitrogen pressures betweenabout 250 and about 5500 psig (about 1.7 and about 37.4 MPa) using a0.0754 mm diameter, 20:1 L/D die with an entrance angle of about 180° C.For the preferred substantially linear ethylene polymers describedherein, the PI is the apparent viscosity (in kpoise) of a materialmeasured by GER at an apparent shear stress of 2.15×10⁶ dyne/^(cm2)(2.19×10⁴ kg/lm²). The substantially linear ethylene polymer for use inthe invention have a PI in the range of 0.01 kpoise to 50 kpoise,preferably 15 kpoise or less. In one exemplary aspect, the substantiallylinear ethylene polymers used herein also have a PI less than or equalto 70 percent of the PI of a linear ethylene polymer (either a Zieglerpolymerized polymer or a homogeneously branched linear polymer asdescribed by Elston in U.S. Pat. No. 3,645,992) having an I₂ andM_(w)/M_(n) each within ten percent of the substantially linear ethylenepolymer.

In another aspect, an apparent shear stress versus apparent shear rateplot is used to identify the melt fracture phenomena and quantify thecritical shear rate and critical shear stress of ethylene polymers.According to Ramamurthy in the Journal of Rheology, 30(2), 337-357,1986, the disclosure of which is incorporated herein by reference, abovea certain critical flow rate, the observed extrudate irregularities maybe broadly classified into two main types: surface melt fracture andgross melt fracture. Typically, surface melt fracture occurs underapparently steady flow conditions and ranges in detail from loss ofspecular film gloss to the more severe form of “sharkskin.” Herein, asdetermined using the above-described GER, the onset of surface meltfracture (OSME) can be characterized at the beginning of losingextrudate gloss at which the surface roughness of the extrudate can onlybe detected by 40×. magnification. As described in U.S. Pat. No.5,278,272, the critical shear rate at the onset of surface melt fracturefor the substantially linear ethylene interpolymers and homopolymers isat least 50 percent greater than the critical shear rate at the onset ofsurface melt fracture of a linear ethylene polymer having essentiallythe same I₂ and M_(w)/M_(n).

Further, gross melt fracture can occur at unsteady extrusion flowconditions and ranges in detail from regular (alternating rough andsmooth, helical, etc.) to random distortions. Preferably, for commercialacceptability to maximize the performance properties of films, coatingsand moldings, surface defects should be minimal, if not absent. Thecritical shear stress at the onset of gross melt fracture for thepreferred substantially linear ethylene polymers used in the invention,especially those having a density less than 0.910 g/cc, is greater than4×10⁶ dynes/cm². In one aspect, the critical shear rate at the onset ofsurface melt fracture (OSMF) and the onset of gross melt fracture (OGMF)will be used herein based on the changes of surface roughness andconfigurations of the extrudates extruded by a GER.

In another aspect, the preferred homogeneously branched ethylenepolymers used in the present invention can be characterized by a singleDSC melting peak. In this aspect, the single melting peak can bedetermined using a differential scanning calorimeter standardized withindium and deionized water. The exemplary method involves 5-7 mg samplesizes, a “first heat” to about 140° C. which is held for 4 minutes, acool down at 10° C./min to −30° C. which is held for 3 minutes, and heatup at 10° C./min. to 150° C. for the “second heat”. The single meltingpeak is taken from the “second heat” heat flow vs. temperature curve.Total heat of fusion of the polymer is calculated from the area underthe curve.

In one aspect, for the preferred homogeneously branched ethylenepolymers having a density of 0.86 g/cc to 0.910 g/cc, the single meltingpeak may show, depending on equipment sensitivity, a “shoulder” or a“hump” on the low melting side that constitutes less than 12 percent,typically, less than 9 percent, and more typically less than 6 percentof the total heat of fusion of the polymer. Such an artifact isobservable for other homogeneously branched polymers such as Exact™resins and is discerned on the basis of the slope of the single meltingpeak varying monotonically through the melting region of the artifact.In this aspect, the artifact can occur within 34° C., typically within27° C., and more typically within 20° C. of the melting point of thesingle melting peak. The heat of fusion attributable to an artifact canbe separately determined by specific integration of its associated areaunder the heat flow vs. temperature curve.

In yet another exemplary aspect, the molecular weight distribution(M_(w)/M_(n)) for the substantially linear ethylene polymers andhomogeneous linear ethylene polymers used in the present invention isgenerally from about 1.8 to about 2.8. However, in another aspect,substantially linear ethylene polymers are known to have excellentprocessability, despite having a relatively narrow molecular weightdistribution. Unlike homogeneously and heterogeneously branched linearethylene polymers, the melt flow ratio (I₁₀/I₂) of substantially linearethylene polymers can be varied essentially independently of theirmolecular weight distribution, M_(w)/M_(n).

In various aspects, the preferred homogeneously branched ethylenepolymers present in the adhesive composition of the present invention(whether present as a virgin polymer, a recycled polymer, or acombination thereof) can comprise interpolymers of ethylene and at leastone α-olefin prepared by a solution, gas phase or slurry polymerizationprocess or combinations thereof. In one example and not meant to belimiting, suitable α-olefins are represented by the following formulaCH₂═CH—R where R is a hydrocarbyl radical. Further, R may be ahydrocarbyl radical having from one to twenty carbon atoms and as suchthe formula includes C₃-C₂₀ α-olefins. Exemplary α-olefins for use ascomonomers can comprise propylene, 1-butene, 1-isobutylene, 1-pentene,1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene, as well as othercomonomer types such as, for example and without limitation, styrene,halo- or alkyl-substituted styrenes, tetrafluoro-ethylene, vinylbenzocyclobutane, 1,4hexadiene, 1,7-octadiene, and cycloalkenes, e.g.,cyclopentene, cyclohexene and cyclooctene. Preferably, the comonomerwill be 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene,1-octene, or mixtures thereof, as adhesive backing materials comprisedof higher α-olefins will have especially improved toughness. However,most preferably, the comonomer will be 1-octene and the ethylene polymerwill be prepared in a solution process.

In an aspect of the invention, the preferred ethylene polymers for usein the present invention have a relative low modulus. That is, theethylene polymer can be characterized as having a 2% secant modulus lessthan 24,000 psi (163.3 MPa), especially less than 19,000 psi (129.3 MPa)and most especially less than 14,000 psi (95.2 MPa), as measured inaccordance with ASTM D790. Additionally, the preferred ethylene polymersfor use in the present invention are substantially amorphous or totallyamorphous. That is, the ethylene polymer is characterized as having apercent crystallinity less than 40 percent, preferably less than 30percent, more preferably less than 20 and most preferably less than 10percent, as measured by differential scanning calorimetry using theequation percent crystallinity=H_(f)/292*100, where H_(f) is the heat offusion in Joules/gram.

In another aspect, it should be understood that either the recycledpolymer portion or the virgin polymer portion of the adhesivecomposition can comprise the preferred homogeneously branched ethylenepolymer blended together with one or more synthetic or natural polymericmaterials. For example and not meant to be limiting, suitable polymersfor blending or mixing with homogeneously branched ethylene polymersused in the present invention can comprise another homogeneouslybranched ethylene polymer, low density polyethylene, heterogeneouslybranched LLDPE, heterogeneously branched ULDPE, medium densitypolyethylene, high density polyethylene, grafted polyethylene (e.g., amaleic anhydride extrusion grafted heterogeneously branched linear lowpolyethylene or a maleic anhydride extrusion grafted homogeneouslybranched ultra low density polyethylene), ethylene acrylic acidcopolymer, ethylene vinyl acetate copolymer, ethylene ethyl acrylatecopolymer, polystyrene, polypropylene, polybutylene, polycarbonate,ethylene propylene polymers, ethylene styrene polymers, and styreneblock copolymers.

In another aspect of the present invention, the recycled polymer portionor the virgin polymer portion of the adhesive composition can comprise amodified homogeneously branched ethylene polymer. In particular, incertain aspects of the invention the at least one homogeneously branchedethylene polymer that can be present within the virgin polymer portionor the recycled polymer portion of the adhesive composition can bemodified by the addition of at least one adhesive polymeric additive.Suitable adhesive polymeric additives include, for example and withoutlimitation, polymer products comprised of (1) one or more ethylenicallyunsaturated carboxylic acids, anhydrides, alkyl esters and half esters,e.g., acrylic acid, methacrylic acid, maleic acid, maleic anhydride,itaconic acid, fumaric acid, crotonic acid and citraconic acid,citraconic anhydride, succinnic acid, succinnic anhydride, methylhydrogen maleate, and ethyl hydrogen maleate; esters of ethylenicallyunsaturated carboxylic acids, e.g., ethyl acrylate, methyl methacrylate,ethyl methacrylate, methyl acrylate, isobutyl acrylate, and methylfumarate; unsaturated esters of carboxylic acids, e.g., vinyl acetate,vinyl propionate, and vinyl benzoate; and ethylenically unsaturatedamides and nitriles e.g., acrylamide, acrylonitrile, methacrylonitrileand fumaronitrile; and (2) one or more ethylenically unsaturatedhydrocarbon monomers such as aliphatic α-olefin monomers, e.g.,ethylene, propylene, butene-1 and isobutene; conjugated dienes, e.g.,butadiene and isoprene; and monovinylidene aromatic carbocyclicmonomers, e.g., styrene, α-methylstyrene, toluene, and t-butylstyrene.

A modified homogeneously branched ethylene polymer for use in the virginpolymer portion of the adhesive composition can be conveniently preparedby known techniques such as, for example, by interpolymerization or by apolymerization procedure followed by a chemical or extrusion graftingprocedure. Suitable grafting techniques are described in U.S. Pat. Nos.4,762,890; 4,927,888; 4,230,830; 3,873,643; and 3,882,194, thedisclosures of all of which are incorporated herein by reference.Further, it should be understood that the presence of the foregoingadhesive polymer additives, whether individually or as a part of amodified homogeneously branched ethylene polymer is due to the presenceof these polymers and polymer additives in the initial post consumercarpet that was recycled as described herein to provide the recycledpolymer portion of the adhesive composition.

Preferred adhesive polymeric additives for use in the present inventioninclude maleic anhydride grafts wherein maleic anhydride is grafted ontoan ethylene polymer at a concentration of about 0.1 to about 5.0 weightpercent, preferably about 0.5 to about 1.5 weight percent. The presenceof ethylene polymer/maleic anhydride grafts as adhesive polymericadditives in the present invention can improve the performance andoperating window of extrusion coated homogeneously branched ethylenepolymers as the adhesive backing material, especially when used inconnection with polar polymers such as for example, but not limited to,nylon and polyester faced carpets. The improvement pertained tosubstantially higher comparative abrasion resistance and tuft bindstrength. In an exemplary aspect, a preferred composition for forming amaleic anhydride graft is the Amplify® GR 204 available from DowChemicals.

Preferred ethylene polymers for use as the grafted host polymer includelow density polyethylene (LDPE), high density polyethylene (HDPE),heterogeneously branched linear low density polyethylene (LLDPE),homogeneously branched linear ethylene polymers and substantially linearethylene polymers. Preferred host ethylene polymers have a polymerdensity greater than or equal to 0.86 g/cc, 0.87 g/cc, 0.88 g/cc, 0.89g/cc, 0.90 g/cc, 0.91 g/cc, 0.92 g/cc, 0.93 g/cc, or even mostpreferably greater than or equal to 0.94 g/cc. Substantially linearethylene polymers and high density polyethylene are the preferred hostethylene polymers.

The actual blending or mixing of various polymers of the adhesivebacking, including the blending of the recycled polymer portion and theoptional virgin polymer portion can be conveniently accomplished by anytechnique known in the art including, but not limited to, melt extrusioncompounding, dry blending, roll milling, melt mixing such as in aBanbury mixer, twin screw extruder, and multiple reactor polymerization.

It will be appreciated that it is contemplated that the adhesivecomposition to be extruded onto the greige good can either be used neat,or can have one or more additive included. In this aspect, the adhesivecomposition of this invention may optionally include exemplary additivessuch as foaming agents, pH controllers, flame retardants, fillers,tackifiers, wetting agents, dispersing agents, anti-microbial agents,lubricants, dyes, anti-oxidants, and the like, which are well known tothose skilled in the art, without loss of the characteristic properties.

In one aspect, the adhesive composition further comprises one or moreflame retardants sufficient to ensure the carpet structure satisfies therequirements of the radiant flux floor covering test according to theASTM-E648 testing procedures. In particular, according to certainaspects, the carpet structures of the present invention exhibit a Class1 critical radiant flux of greater than 0.45 watts per cm² as measuredaccording to ASTM-E648. According to other aspects of the invention, thecarpet structures described herein can exhibit a Class 2 criticalradiant flux in the range of from 0.22 to 0.44 watts per cm² as measuredaccording to ASTM-E648. In still further aspects, the carpet structuresof the present invention can exhibit an unclassifiable critical radiantflux of less than 0.22 watts per cm² as measured according to ASTM-E648.

Exemplary flame retardants that can be incorporated into the adhesivebacking compositions of the present invention include, withoutlimitation, organo-phosphorous flame retardants, red phosphorousmagnesium hydroxide, magnesium dihydroxide, hexabromocyclododecane,bromine containing flame retardants, brominated aromatic flameretardants, melamine cyanurate, melamine polyphosphate, melamine borate,methylol and its derivatives, silicon dioxide, calcium carbonate,resourcinol bis-(diphenyl phosphate), brominated latex base, antimonytrioxide, strontium borate, strontium phosphate, monomeric N-alkoxyhindered amine (NOR HAS), triazine and its derivatives, high aspectratio talc, phosphated esters, organically modified nanoclays andnanotubes, non-organically modified nanoclays and nanotubes, ammoniumpolyphosphate, polyphosphoric acid, ammonium salt, triaryl phosphates,isopropylated triphenyl phosphate, phosphate esters, magnesiumhydroxide, zinc borate, bentonite (alkaline activated nanoclay andnanotubes), organoclays, aluminum trihydrate (ATH), azodicarbonamide,diazenedicarboxamide, azodicarbonic acid diamide (ADC), triarylphosphates, isopropylated triphenyl phosphate, triazine derivatives,alkaline activated organoclay and aluminum oxide. Any desired amount offlame retardant can be used in the adhesive compositions of the instantinvention and the selection of such amount will depend, in part, uponthe particular flame retardant used, as well as the desired level offlame retardance to be achieved in the second generation carpet beingmanufactured. Such amounts can be readily determined through no morethan routine experimentation.

Exemplary and non-limiting fillers that can be incorporated into theadhesive backing composition of the present invention can includecalcium carbonate, flyash, residual by products from thedepolymerization of Nylon 6 (also referred to as ENR co-product),recycled calcium carbonate, aluminum trihydrate, talc, nano-clay, bariumsulfate, barite, barite glass fiber, glass powder, glass cullet, metalpowder, alumina, hydrated alumina, clay, magnesium carbonate, calciumsulfate, silica, glass, fumed silica, carbon black, graphite, cementdust, feldspar, nepheline, magnesium oxide, zinc oxide, aluminumsilicate, calcium silicate, titanium dioxide, titanates, glassmicrospheres, chalk, calcium oxide, and any combination thereof. In onepreferred aspect, the recycled adhesive composition comprises inorganicfiller with high heat content. In some aspects, it is preferred for thefiller to exhibit relatively high heat content. Examples of such fillersinclude, but are not limited to, calcium carbonate, aluminum trihydrate,talc, and barite. The exemplified high heat content fillers allow theextrudate to remain at elevated temperatures longer with the beneficialresult of providing enhanced encapsulation and penetration. In thisaspect, the high heat content fillers should be ground or precipitatedto a size that can be conveniently incorporated in an extrusion coatingmelt stream. Exemplary non-limiting particle sizes for the inorganicfiller material can include particle sizes in the range of from about 1to about 50 microns. Still further, it should also be understood thatthe filler component can be present in any desired amount. However, inan exemplary aspect, the filler is present in an amount in the range offrom 25 weight % to 90 weight %, based upon the total weight of theadhesive composition, including exemplary amounts of 30 weight %, 35weight %, 40 weight %, 45 weight %, 50 weight %, 55 weight %, 60 weight%, 65 weight %, 70 weight %, 75 weight %, 80 weight %, and 85 weight %.Still further, the amount of filler present can be in any range derivedfrom any two of the above stated weight percentages.

In still another aspect, the adhesive composition can further compriseone or more tackifying additives. The tackifier can for example be talloil or rosin based or, alternatively, can be an aliphatic or aliphaticaromatic hydrocarbon blend resin. In an exemplary aspect, the tackifiercan be a hydrocarbon tackifier such as the Piccotac 1115 tackifieravailable from Eastman Chemical Company, Kingsport, Tenn., USA. As thetackifier is an optional component, the amount of tackifier can be, whenpresent, in the range of from greater than 0 weight percent up to andeven exceeding 50 weight percent of the adhesive composition. Forexample, in one aspect, the amount of tackifier can be in the range offrom 5 weight percent to 45 weight %. In still another aspect, theamount of tackifier can be in the range of from 10 weight % to 20 weight%.

In still another aspect, the adhesive backing can be a foamed adhesivebacking. To that end, if a foamed backing is desired on the carpet, ablowing agent can be added to the adhesive backing material and/or theoptional secondary backing material. If used, the blowing agents arepreferably conventional, heat activated blowing agents such as, withoutlimitation, azodicarbonamide, toluene sulfonyl semicarbazide, and oxybis(benzene sulfonyl) hydrazide. In this aspect, it is contemplated thatthe selected implosion agent is formulated into the adhesive backingmaterial and the extrusion conditions are set such that the activationof the implosion agent occurs at the instant of nip while the adhesivebacking material is still semi-molten or molten. With improved yarnpenetration accomplished with the use of an implosion agent, the carpetwill exhibit comparatively improved abrasion resistance. Thus, the useof an implosion agent can allow the use of polymer compositions havinglower molecular weights to provide improved extrusion coatability yetmaintain higher abrasion resistance (i.e., comparable to adhesivebacking materials based on higher molecular weight polymercompositions).

Conventional blowing agents or any material that ordinarily functions asa blowing agent can be used as an implosion agent in the presentinvention providing expansion of the adhesive backing material matrix issuitably restricted or confined when the material is activated such thatmolten polymer is forced into the interior and free space of the yarn orfiber bundles and there is no substantial expansion of the adhesivebacking material as a result of having used the implosion agent.

Still further, it should be understood that yet other additives can alsobe included in the adhesive backing material of the present invention,including for example and without limitation, antioxidants such assterically hindered phenols, sterically hindered amines and phospitesmay be used. Suitable antioxidants can include, for example, a hinderedphenol and a phosphite. Other possible additives include antiblockadditives, pigments and colorants, anti-static agents, antimicrobialagents (such as quaternary ammonium salts) and chill roll releaseadditives (such as fatty acid amides).

In still another broad aspect, the present invention also provides amethod for manufacturing the carpets described herein. While, as noted,carpet and carpet tiles are separate aspects of the present invention,the basic structure of the face fabric of these aspects are not criticalto the invention and, as such, will be discussed together.

In a first aspect of the present invention, a face fabric is provided.The face fabric can be either a tufted greige good, a fusion bondedmaterial or a woven and needle punched material. Whether a tufted greigegood, a fusion bonded or a woven and needle punched face fabric is used,the face yarns may be made from synthetic fibers such as, for exampleand without limitation, polyolefins, polyamides, polyesters,polyethylene terephthalate (PET), polypropylene, and polytrimethyleneterephthalate (PTT). Still further, the face yarns can be comprised ofnatural fibers such as staple rayon fibers, cellulose fibers, cottonfibers, viscose, and combinations thereof. In a particularly preferredaspect, the face yarns are comprised of polypropylene. In anotherpreferred aspect, the face yarns are comprised of nylon fibers.

To prepare a greige good, a yarn is tufted, woven or needle punched intoa primary backing. The tufting, weaving or needle punching can beconducted in any manner known to be suitable to one of ordinary skill inthe art which will not be discussed in detail herein. To fix the yarn tothe primary backing, an adhesive material is applied to the back of thefabric. In one aspect of the present invention, the adhesive materialapplied to the back side of the fabric is comprised of a recycledadhesive backing composition as described herein. However, in analternative aspect, and as described in more detail below, a pre-coatlayer can first be applied to the backside of the fabric in order to fixthe yarn to the primary backing prior to applying the recycled adhesivebacking material of the present invention.

In the present invention, a woven or a non-woven primary backingmaterial can be used. The type of primary backing desired will depend onvarious factors including, but not limited to, whether broadloom carpet,carpet tile, or an area rug is being made, the desired end-use for theproduct (e.g., commercial or residential), the type of face yarn usedand the price of the product. One example of a suitable woven primarybacking is 24×18 woven primary, style no. 2218 from Propex, Inc. Oneexample of a suitable non-woven backing material is Colbond UMT 135,manufactured by Colbond, Enka, N.C. Other types of primary backings arealso suitable for use herein such as, for example, hydraentangled fibersand fiberglass.

A fusion bonded face fabric is characterized by a plurality of cut pileyarns, for example, nylon or other natural or synthetic fibrous-typematerial, implanted in an adhesive layer, particularly a thermoplastic,like a polyvinyl chloride layer or a hot-melt adhesive layer. Where apolyvinyl chloride plastisol layer is used, heating of the layer gelsand then fuses the layer into solid form, while with hot-melt adhesivematerial, a melted layer is applied and subsequently cooled into solidform. The plurality of fibrous yarns are bonded to and extend uprightfrom the adhesive base layer to form a face wear surface. Methods ofmaking fusion bonded face goods are known and described, for example, inU.S. Pat. No. 6,089,007, the disclosure of which is incorporated in itsentirety by this reference.

In another aspect, any conventional tufting or needle-punching apparatusand/or stitch patterns can be used in the carpet of the presentinvention. Likewise, it does not matter whether tufted yarn loops areleft uncut to produce a loop pile; cut to make cut pile; or cut,partially cut and uncut to make a face texture known as tip sheared.After the yarn is tufted or needle-punched into the primary backingmaterial, the greige good can be conventionally rolled up with the backside of the primary backing material facing outward and held until it istransferred to the backing line.

In one exemplary embodiment, the greige good can be scoured or washedbefore it has an adhesive backing material extruded thereon to remove ordisplace all or substantially all of the processing materials, such asfor example oily or waxy chemicals, known as spin-finish chemicals, thatremain on the yarn from the yarn manufacturing processes. It is alsocontemplated that the use of polyolefin waxes (rather than conventionalorganic and mineral oils) as processing materials would allow improvedadhesive backing material performance in itself or at least minimize theuse of scouring or washing methodologies.

As noted, according to some aspects of the invention, the greige goodcan optionally be coated with a pre-coat material (not shown) before theadhesive backing material is extruded thereon. The aqueous pre-coatmaterial can, for example, be added as a dispersion or as an emulsion.In an exemplary aspect, an emulsion can be made from various polyolefinmaterials such as, for example and without limitation, ethylene acrylicacid (EAA), ethylene vinyl acetate (EVA), polypropylene or polyethylene(e.g., low density polyethylene (LDPE), linear low density polyethylene(LLDPE) or substantially linear ethylene polymer, or mixtures thereof).It is further contemplated that the pre-coat material can be selectedfrom a group comprising, without limitation, an EVA hotmelt, a VAEemulsion, carboxylated styrene-butadiene (XSB) latex copolymer, a SBRlatex, a BDMMA latex, an acrylic latex, an acrylic copolymer, a styrenecopolymer, butadiene acrylate copolymer, a polyolefin hotmelt,polyurethane, polyolefin dispersions and/or emulsions, and anycombination thereof.

When used, the pre-coat can further comprise one or more flameretardants. Exemplary flame retardants that can be incorporated into theoptional pre-coat layer include, without limitation, organo-phosphorousflame retardants, red phosphorous magnesium hydroxide, magnesiumdihydroxide, hexabromocyclododecane, bromine containing flameretardants, brominated aromatic flame retardants, melamine cyanurate,melamine polyphosphate, melamine borate, methylol and its derivatives,silicon dioxide, calcium carbonate, resourcinol bis-(diphenylphosphate), brominated latex base, antimony trioxide, strontium borate,strontium phosphate, monomeric N-alkoxy hindered amine (NOR HAS),triazine and its derivatives, high aspect ratio talc, phosphated esters,organically modified nanoclays and nanotubes, non-organically modifiednanoclays and nanotubes, ammonium polyphosphate, polyphosphoric acid,ammonium salt, triaryl phosphates, isopropylated triphenyl phosphate,phosphate esters, magnesium hydroxide, zinc borate, bentonite (alkalineactivated nanoclay and nanotubes), organoclays, aluminum trihydrate(ATH), azodicarbonamide, diazenedicarboxamide, azodicarbonic aciddiamide (ADC), triaryl phosphates, isopropylated triphenyl phosphate,triazine derivatives, alkaline activated organoclay and aluminum oxide.Any desired amount of flame retardant can be used in the precoat and theselection of such amount will depend, in part, upon the particular flameretardant used, as well as the desired level of flame retardance to beachieved in the second generation carpet being manufactured. Suchamounts can be readily determined through no more than routineexperimentation.

In still a further aspect, the precoat can preferably contain otheringredients. For example, a surfactant can be included to aid in keepingthe polyolefin particles at least substantially dispersed. Suitablesurfactants can include, for example and without limitation, nonionic,anionic, cationic and fluorosurfactants. Preferably, the surfactant ispresent in an amount between about 0.01 and about 5 weight percent basedon the total weight of the emulsion or dispersion. More preferably, thesurfactant is anionic.

In another example, the pre-coat can further comprise a thickener, adefoaming agent, and/or a dispersion enhancer. In this aspect, thethickener helps to provide a suitable viscosity to the dispersion. Forexample, the thickener can exemplarily comprise sodium and ammoniumsalts of polyacrylic acids and best present in an amount between about0.1 and about 5 weight percent based on the total weight of thedispersion. The defoaming agent can, without limitation, be anon-silicone defoaming agent and is present in an amount between about0.01 and about 5.0 weight percent based on the total weight of thedispersion. An exemplified dispersion enhancer can be a fumed silicathat acts as a compatibilizer for the dispersion, which allows for theuse of larger polyolefin particles. Preferably, the fumed silica ispresent at between about 0.1 and about 0.2 weight percent based on thetotal weight of the dispersion.

In still another aspect, the pre-coat can comprise one or more fillers.Exemplary and non-limiting fillers that can be incorporated into theadhesive backing composition of the present invention can includecalcium carbonate, flyash, residual by products from thedepolymerization of Nylon 6 (also referred to as ENR co-product),recycled calcium carbonate, aluminum trihydrate, talc, nano-clay, bariumsulfate, barite, barite glass fiber, glass powder, glass cullet, metalpowder, alumina, hydrated alumina, clay, magnesium carbonate, calciumsulfate, silica, glass, fumed silica, carbon black, graphite, cementdust, feldspar, nepheline, magnesium oxide, zinc oxide, aluminumsilicate, calcium silicate, titanium dioxide, titanates, glassmicrospheres, chalk, calcium oxide, and any combination thereof.

The pre-coat can be applied to the carpet in various ways. For example,the dispersion can be applied directly, such as with a roll over rollerapplicator, or a doctor blade. Alternatively, the pre-coat can beapplied indirectly, such as with a pan applicator. It is contemplatedthat the amount of pre coat applied and the concentration of theparticles in the pre-coat can be varied depending on the desiredprocessing and product parameters. In one example, the amount ofdispersion applied and the concentration of the particles are selectedso as to apply between about 4 and about 12 ounces per square yard(OSY).of carpet. In one aspect, this can be achieved by using adispersion or emulsion containing about 50 weight percent polyolefinparticles (based on the total weight of the emulsion) and applyingbetween about 8 and about 30 OSY of the dispersion. Accordingly, itshould be understood that desired application weight of the pre-coatwill depend, at least in part, upon the presence and amount of inorganicfillers and/or flame retardants in the pre-coat. In an exemplary aspect,a preferred a latex precoat is the LXC 807 NA from Dow Chemicals.

After application of the pre-coat, heat can be applied to the back sideof the primary backing so as to dry, melt, and/or cure the emulsion. Asa result, the loops of yarn can be at least partially fixed to theprimary backing. Preferably, the heat is applied by passing the productthrough an oven.

After treatment with the optional pre-coat emulsion of polyolefinparticles, additional backing material can be applied thereto. Theadditional backings can be applied by various methods with the preferredmethod involving the use of an extruded sheet of a thermoplasticmaterial, preferably the recycled adhesive backing composition asdescribed above, onto which a conventional secondary backing can also belaminated. In particular, a molten thermoplastic material is preferablyextruded through a die so as to make a sheet which is as wide as thecarpet. The molten, extruded sheet is applied to the back side of theprimary carpet backing. Since the sheet is molten, the sheet willconform to the shape of the loops of yarn and further serve toencapsulate and fix the loops in the primary backing. In aspects where apre coat has been applied to the back side of the greige good, it willbe understood that the pre-coat is disposed between the adhesive backingcomposition and the back side of the greige good. Alternatively,according to aspects where the optional pre coat layer is not applied,the recycled adhesive backing composition of the present invention isapplied directly on the back side of the primary backing and can,itself, serve to fix the loops in the primary backing.

Exemplary extrusion coating configurations can include, withoutlimitation, a monolayer T-type die, single-lip die coextrusion coating,dual-lip die coextrusion coating, a coat hanger die, and multiple stageextrusion coating. Preferably, the extrusion coating equipment isconfigured to apply a total coating weight of from about 4 to about 60ounces/yd² (OSY), including exemplary amounts of 5, 10, 15, 20, 25, 30,35, 40, 45, 50 and 55 ounces/yd² (OSY), and any range of coating weightsderived from these values. To that end, it should be understood that thedesired coating weight of the extrusion coated layers will depend, atleast in part, upon the amount of any flame retardants or inorganicfillers in the extrudate.

The extrusion coating melt temperature principally depends on theparticular composition of the adhesive backing composition beingextruded. When using the recycled adhesive backing composition describedabove, comprising the preferred substantially linear polyethylenedescribed above, the extrusion coating melt temperature can be greaterthan about 350° F. and, in some aspects, in the range of from 350° F. to650° F. In another aspect, the melt temperature can be in the range offrom 375° F. to 600° F. Alternatively, the melt temperature can be inthe range of from 400° F. to 550° F. Still further, in aspects of theinvention the melt temperature can be in the range of from 425° F. to500° F.

FIG. 4. shows an exemplary line 400 for applying a recycled adhesivebacking composition as described herein to the back side of a greigegood to provide an adhesive backed carpet 470. As shown, the line 400includes an extruder 421 equipped with a slot die 422, a nip roll 424, achill roll 423, an exhaust hood 426, a turn roll 428 and a pre-heater425. As illustrated, the nip roll is preferably equipped with a vacuumslot 429 to draw a vacuum across about a portion of its circumferenceand is configured in communication with a vacuum pump 427. The slot die422 is configured to dispense the recycled adhesive backing material inthe form of a semi-molten or molten polymer sheet 430 onto greige good440 with the polymer sheet 330 being oriented towards the chill roll 423and the greige good 440 being oriented towards the optional vacuum niproll 424. As further illustrated, an optional secondary backing material450 can be applied onto the polymer sheet 430. The point where the niproll 424 and the chill roll 423 are closest to one another is referredto as the nip 460.

It is further contemplated according to aspects of the present inventionthat a plurality of two or more separate layers or applications of arecycled adhesive backing composition of the present invention can beapplied to the backside of a greige good. For example, in aspect wherethe optional pre-coat as described above has not been applied, it can bedesirable to apply a first layer of the recycled adhesive backingcomposition to first fix the yarn loops to the primary backing, followedby a subsequent application of a recycled adhesive composition of theinstant invention. To that end, it is contemplated that a carpet withtwo layers of extruded recycled adhesive backing can be made with asingle extrusion die, nip roll and chill roll similar to that depictedin FIG. 4. In particular, a first layer of extruded backing can beapplied in a first pass through the line after which the carpet isrolled up. The second layer of extruded backing can then be applied ontop of the first layer in a second pass through the same line.

According to aspect having two or more extruded layers of the recycledadhesive backing composition, the two layers can optionally be comprisedof the same adhesive backing composition or, alternatively, canoptionally each be a layer comprising a different adhesive backingcomposition. For example, a first layer can be applied directly onto thebackside of the primary backing material (first layer) having a highermelt index than the second layer which is applied onto the backside ofthe first layer. In this aspect, since it is the first layer which isrelied on to encapsulate and penetrate the yarn, this layer should havea melt index high enough (melt viscosity low enough) to promoteencapsulation and penetration of the yarn. The second layer, which isgenerally not relied on to encapsulate and penetrate the yarn, may beused either as the bottom surface of the carpet or to facilitate theapplication of an optional secondary backing material. In this example,it can be preferred to have a lower melt index to provide higherstrength after cooling. Further, a resin of lower quality and/or lesstightly controlled properties may be used in the second layer because itis not relied on for encapsulating or penetrating the fiber bundles. Ina preferred embodiment, the second layer can be formed from a recycledadhesive composition. In this aspect, it is contemplated that the firstand second layers can consist of different polymer chemistries orcompositions.

In still another aspect, two or more layers of a single polymercomposition can be extruded to provide greater control over thethickness or weight of the adhesive backing applied to the carpet. Stillfurther, in alternative embodiments, three or more layers of theadhesive backing composition can be extruded on the back surface of theprimary backing material to achieve even higher coat weights and/or toobtain a more gradual transition between the first and last layerapplied. In this aspect, a dual lip die can be used to apply two layers.Alternatively, two or more extrusion stations or a single lipcoextrusion die can be used to apply these two or more layers.

In still another aspect, it can also be desired to apply a reinforcinglayer to the adhesive backing layer of the carpet. The reinforcing layercan, for example, add dimensional stability to those aspects of theinvention that are intended for use as carpet tiles. To that end, anyconventional reinforcing material can be used, including woven andnon-woven fiberglass or polypropylene scrims and the like. In apreferred aspect, the scrim can be applied in between two or more layersof the recycled adhesive backing composition. For example, FIG. 5schematically shows an exemplary line 520 for manufacturing a carpetaccording to aspects of the present invention. As shown, a length ofgreige good 521, i.e., yarn tufted into a primary backing, is unrolledfrom the roll 523. The greige good 521 passes over the rollers 525 and527 with the primary backing toward a pre-heater 529. The pre-heater,such as a convection oven or infrared panels, can be used to heat theback of the greige good before the adhesive backing material is extrudedthereon to enhance the encapsulation and penetration of the yarnbundles. In addition to or as an alternative to pre-heating, the processof the invention may also employ a post-heat soaking process step tolengthen the molten time for the adhesive backing material to therebyimprove the encapsulation and penetration of the yarn or fiber bundlesby the adhesive backing material.

An extruder 531 is mounted so as to extrude a first sheet 535 of therecycled adhesive backing composition through the die 533 and onto theback of the greige good at a point between the roller 527 and the niproll 541. The exact location at which the sheet 535 contacts the greigegood can be varied depending on the line speed and the time desired forthe molten polymer to rest on the greige good before passing between thenip roll 541 and the chill roll 543. In this depicted embodiment, ascrim of non-woven fiberglass 539 can be fed from roll 537 so as tocontact the chill roll 543 at a point just prior to the nip roll 541. Asa result, the scrim 539 that will act as a reinforcing fabric in thefinished carpet is laminated to the greige good through the polymer.

The desired pressure between the nip roll 541 and the chill roll 543,measured in pounds per linear inch (PLI) can be varied depending on theforce desired to push the extruded sheet. In particular, this desiredpressure can be adjusted by varying the pressure within the aircylinders. Alternatively, the nip roll 541 and chill roll 543 can beoperated in a gap mode whereby the spacing between the two rolls can beadjusted to a desired gap width, depending for example on the thicknessof the material being passed therebetween. Also, as described inconnection with FIG. 4, it may be desirable to include a vacuum slot inthe nip roll. In addition, a jet of pressurized air may also be used topush the extruded sheet into the carpet backing. Still further, the sizeof the chill roll 543 and the length of time the carpet rolls against itcan be varied depending on the level of cooling desired in the process.Preferably, the chill roll 543 is cooled by simply passing ambient orchilled water through it.

After passing over the chill roll 543, the carpet is brought overrollers 545 and 547 with the carpet pile oriented toward the rollers andthe backside of the carpet, having a first layer of adhesive 535 and ascrim 539 laminated thereto oriented toward a second pre-heater 563. Asecond extruder 549 extrudes a second sheet of a recycled adhesivebacking composition 553 through its die 551 on to the back of the scrim539. Again the point at which the extruded sheet 553 contacts the scrim539 can be varied as described above.

At this point, if an optional secondary backing fabric 567 is desiredfor the carpet composition, that fabric can be introduced from a secondroll 565 similar to that shown at 537 so as to be laminated to thecarpet through the extruded sheet 553 as it passes between the nip roll555 and the chill roll 557. Subsequently, the carpet passes between thenip roll 555 and the chill roll 557. Again, the pressure applied betweenthe two rolls 555 and 557 can be varied as required. Finally, afterpassing around the chill roll 557, the finished carpet 561 passes aroundroll 559 and is preferably passed over an embossing roll (not shown) toprint a desired pattern on the back of the carpet.

As noted above, the carpet of the invention can optionally include asecondary backing material. As shown in FIG. 4 and FIG. 5, the secondarybacking material is preferably laminated directly to the extrudedlayer(s) while the extrudate is still molten after extrusion coating toimprove the penetration of the extrusion coating into the primarybacking. Alternatively, the secondary backing material can be laminatedin a later step by reheating and/or remelting at least the outermostportion of the extruded layer or by a coextrusion coating techniqueusing at least two dedicated extruders. Also, the secondary backingmaterial can be laminated through some other conventional means, such asby interposing a layer of a polymeric adhesive material between theadhesive backing material and the secondary backing material. Suitablepolymeric adhesive materials include, but are not limited to, ethyleneacrylic acid (EAA) copolymers, ionomers and maleic anhydride graftedpolyethylene compositions. The secondary backing material can be wovenor non-woven and can further be comprised of one or more polyethylenepolymers such as, for example and without limitation, a low densitypolyethylene (LDPE), heterogeneously branched linear low densitypolyethylene (LLDPE), high density polyethylene (HDPE), heterogeneouslybranched ultra low density polyethylene (ULDPE), heterogeneouslybranched very low density polyethylene (VLDPE), heterogeneously branchedlinear low density polyethylene (LLDPE), heterogeneously branched linearvery low density polyethylene (VLLDPE), a copolymer of ethylene andalpha olefin, polypropylene, a copolymer of propylene and alpha olefin,a copolymer of propylene and ethylene, ethylene vinyl acetate copolymer(EVA), ethylene methyl acrylate copolymer (EMA), grafted polyethylenepolymers (e.g., a maleic anhydride extrusion grafted heterogeneouslybranched linear low polyethylene or a maleic anhydride extrusion graftedhomogeneously branched ultra low density polyethylene), ethylene acrylicacid copolymer, ethylene ethyl acrylate copolymer, polystyrene,polyolefin, polyester, polyurethane, polybutylene, polyamide,polycarbonate, rubbers, ethylene propylene polymers, ethylene styrenepolymers, styrene block copolymers, and vulcanates.

In still another aspect, the extrusion backed carpet construction andthe methods described herein are particularly suited for making carpettile. FIG. 6 shows an exemplary cross-section of a carpet tile 600 madeaccording to the present invention. A face yarn 603 is tufted into aprimary backing 601 so as to leave a carpet pile face 604 on top of theprimary backing 601 and back stitches 605 below the primary backing.Applied to the back of the primary backing 601 and the back stitches 605is a recycled adhesive composition layer 607 comprising at least onerecycled polyolefin polymer component reclaimed from a process asdescribed herein. In a preferred embodiment of carpet tile, the carpetincludes from about 5 to about 200 OSY of extruded adhesive backing.More preferably, the carpet for tile includes from about 30 to about 80OSY of extruded backing, most preferably, 50 OSY

Preferably, the carpet tile receives its extruded adhesive backing intwo passes as exemplified in FIG. 5 discussed above. The first passapplies the layer 607. Preferably this layer 607 is between about 2.5and about 100 OSY of the extruded polymer, more preferably between about15 and about 40 OSY, and most preferably 25 OSY. The second pass addsthe layer 611. Preferably the second layer 611 is about 2.5 and about100 OSY, more preferably between about 15 and 40 OSY, and mostpreferably 25 OSY.

When, for example, making carpet tile, it can again be preferable toembed a layer of reinforcing material 609 between the first and secondlayers of extruding backing. An important property of carpet tile isdimensional stability, i.e., the ability of the tile to maintain itssize and flatness over time. The inclusion of this layer of reinforcingmaterial has been found to enhance the dimensional stability of carpettile made according to this preferred embodiment. Suitable reinforcingmaterials include dimensionally and thermally stable fabrics such asnon-woven or wet-laid fiberglass scrims, as well as woven and non-woventhermoplastic fabrics (e.g. polypropylene, nylon and polyester). Mostpreferably, the reinforcement layer is a polypropylene non-woven fabricsold by Reemay as “Typar” with a basis weight of 3.5 OSY. Alternatively,a preferred reinforcement layer is a fiberglass scrim sold by ELK Corp.as “Ultra-Mat” with a basis weight of 1.4 OSY.

The carpet tile may include a secondary backing fabric 613 below thesecond layer of extruded backing 611. Suitable materials for thesecondary backing fabric include those described above.

One skilled in the art will appreciate that, notwithstanding theparticular examples described above, it is contemplated that the carpetmay be produced by the processes known to those of skill in the art,including but not limited to direct coating and roll metering, andknife-coating and lick-roll application, as described in D. C. Blackly,Latex and Textiles, section 19.4.2, page 361, which is incorporatedherein by reference.

EXAMPLES

To further illustrate the principles of the present invention, thefollowing examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thevarious aspects of the invention disclosed herein can be made and/orevaluated. They are intended to be purely exemplary of the invention andare not intended to limit the scope of what the inventors regard astheir invention. Efforts have been made to ensure accuracy with respectto numbers (e.g., amounts, temperatures, etc.); however, some errors anddeviations may have occurred. Unless indicated otherwise, parts areparts by weight, temperature is degrees C. or is at ambient temperature,and pressure is at or near atmospheric or full vacuum.

Example 1 Evaluation of Melt Flow Ratio and Reclamation for ControlSamples

A series of experiments were performed to evaluate the melt flow ratioand recyclability of exemplary adhesive components. These melt flowratios were then compared to the melt flow ratios of an exemplary virginadhesive composition. Without intending to be bound by theory, it isbelieved that melt flow ratio can, in one aspect, be indicative of theprocessing characterstics of a polymeric adhesive composition andtherefore a correlation or similarity in the measured melt flow ratioscan, in one aspect, be indicative of the ability for a recycle adhesivecomposition according to the present invention to be utilized inpreparing a second generation carpet composition.

Initially, a control sample comprised of virgin adhesive components wasevaluated for its melt flow processing characteristics. The controlsample was a polymeric adhesive composition comprised of approximately75 weight percent of an Affinity® series substantially linear ethylenepolymer from Dow Chemicals, approximately 20 weight percent of ahydrocarbon tackifier resin (Piccotac 1115 from Eastman Chemical), and 5weight % of an adhesive modifier (GR 204 from Dow Chemical). Fivesamples of the control composition were tested according to ASTMD1238-04C and the resulting data are set forth in Table 1 below:

TABLE 1 Melt Flow Ratio of Virgin Control Samples Control 1 58.36 g/10min Control 2 59.89 g/10 min Control 3 55.12 g/10 min Control 4 48.02g/10 min Control 5 46.52 g/10 min Average 53.58 g/10 min

The control adhesive composition, comprised of virgin adhesivecomponents as set forth above, was then evaluated for its ability to bedissolved in a terpene solvent system and subsequently reclaimedpursuant to the method of the instant invention. The recycling methodcomprised preheating a vacuum oven to approximately 200 degrees Celsius.A sample of the extruded control virgin adhesive layer was obtained andsubsequently size reduced to polymer chips less than approximately 0.25inches in size.

Using a round-bottomed 250 ml flask, approximately 60.0 grams ofD-Limonene and 6.0 g of polymer chips were combined. A magnetic stir barwas then added to the flask for mechanical agitation. Prior to heatingthe sample, the air in the flask was purged with a CO₂ gas stream. Afterwhich, the sample was heated with the CO₂ blanket in place. Around-bottomed heating mantle was used to evenly distribute heat to theliquid sample. The stir bar was activated at a medium agitation level tokeep the polymer chips moving off of the glassware during heating. Thesample was heated slowly until nearly boiling and the chips were allowedto dissolve into solution.

As the CO₂ blanket was pushed out of the container by D-limonene vapor,a condenser and solvent recovery apparatus was connected to collect thedistilled D-limonene from the flask. The sample continued to heat slowlywhile the majority of the D-limonene distilled. The heat was graduallyincreased as the volume of liquid dropped being careful not to superheatto speed up the process. The dissolved polymer composition wasdevolatilized until the stirbar nearly or completely stopped spinningdue to the viscosity increase resulting from the solvent removal. Onceno more solvent was being devolatilized, the heat source was removed.

After removal of the heat, the flask was again filled with CO₂ gas toprevent oxidation of the sample and then sealed with a stopper. Thesample was allowed to cool under ambient conditions until the glasswarecould safely be handled. Once cool, the recovered polymer was scrapedout of the glassware and place into a PTFE-coated watch glass (6″diameter). The polymer-filled PTFE watch glass was then placed in thepre-heated vacuum oven under a Nitrogen blanket. The vacuum pump wasengaged and the nitrogen purge was run for approximately 30 seconds.After which, the nitrogen valve was closed and the vacuum pump was runin order to reach approximately 29.5″ or greater vacuum pressure.

The sample was allowed to dwell, under full vacuum pressure, at 200 Cfor 16 hours. This vacuum drying removed the residual solvent that wascontained in the recovered polymer and that typically cannot be removedin atmospheric distillation conditions. Once the vacuum drying wascomplete, the oven chamber was again filled with N₂ until the vacuumpressure was released. The sample was then removed from the oven andallowed to cool in ambient conditions.

Once the recovered polymer sample was cooled, nine samples of therecovered control polymer composition were again tested for its MeltFlow Rate properties using the same method as the control. The resultingmelt flow rates are set forth in Table 2 below.

TABLE 2 Melt Flow Properties of Reclaimed Control Sample RecoveredControl Sample 1 46.52 g/10 min. Recovered Control Sample 2 49.72 g/10min. Recovered Control Sample 3 47.79 g/10 min. Recovered Control Sample4 49.16 g/10 min. Recovered Control Sample 5 53.11 g/10 min. RecoveredControl Sample 6 48.48 g/10 min. Recovered Control Sample 7 51.72 g/10min. Recovered Control Sample 8 53.48 g/10 min. Recovered Control Sample9 59.68 g/10 min. Average of Recovered Samples 1-9 51.07 g/10 min.

When compared to the initial melt flow characteristics of the virgincontrol samples set forth in Table 1 above, the results of the melt flowrates for the recovered control samples indicate that the recoveredpolymer from the extruded adhesive layer would have similar processingcharacteristics to that of virgin adhesive composition.

Additionally, a mass balance and polymer quality study was performed todetermine the residual level of any solvent remaining in the recoveredpolymer. In particular, pursuant to the control samples set forth above,it was determined that at 200 degrees C., at a dwelling time of about 16hours and under 29.5″ of vacuum, the control polymer samples were ableto achieve an exemplified residual level of solvent in the range of fromapproximately 0% to 0.26%. The data obtained and used for thisdetermination is set forth in Table 3 below.

TABLE 3 Sample # Starting Mass Final Mass Residual Control 1 5.04 grams5.04 grams   0% Control 2 5.01 grams 5.07 grams 0.12% Control 3 5.04grams 5.17 grams 0.26%

Example 2 Exemplary Adhesive Reclamation from Actual Carpet Composition

The method of the instant invention was evaluated for its ability toreclaim polymeric materials from an actual carpet composition. A seriesof eleven reclamation experiments were conducted on a carpet compositionthat was a tufted broadloom carpet construction having a total materialweight of approximately 57.92 oz/sy, including a total yarn weight ofapproximately 26.6 oz/sy and a total polymer weight of approximately31.32 oz/sy. The yarn was a nylon yarn, tufted into a polypropyleneprimary backing having a weight of approximately 3.2 oz/sy. A latexprecoat, LXC 807 NA from Dow Chemicals was applied to the primarybacking in an amount of approximately 5.16 oz/sy. A virgin adhesivecomposition as described above in reference to the control sample wasapplied to the primary backing in an amount of approximately 19.24oz/sy. A non-woven polypropylene secondary backing was also applied,having a total weight of approximately 3.68 oz/sy.

Pursuant to this example, a vacuum oven was again preheated to 200degrees Celsius. The carpet described above was size reduced to intoapproximately ˜½″×½″ pieces. Using a round-bottomed 250 ml flask,approximately 6.00 grams of the sized reduced carpet pieces andapproximately 60.00 grams of D-Limonene were combined. A magnetic stirbar was also added for mechanical agitation. The “air” in the flask waspurged using CO2 gas prior to heating the sample. The sample was heatedwith the CO2 blanket in place, using a round-bottomed heating mantle toevenly distribute heat to the liquid sample. The stir bar was thenengaged to a medium agitation level to keep the carpet pieces moving offof the glassware during heating. The sample was slowly heated until itnearly boiled, allowing the sample to dissolve into the solvent.

Once the non-nylon components of the carpet had dissolved into theD-Limonene solution, the flask was removed from the heating mantle. Amesh screen material (60 mesh) was then cut to fit a Buchner funnel.Once the mesh filter was placed in the Buchner funnel, the funnel wasplaced over an empty round bottomed flask. The dissolved polymermixture, liquid, yarn, etc. was then filtered through the Buchner funneland screen to collect the polymer solution and to separate thenon-dissolved components, such as the nylon yarn. The collected yarn wasthen washed three times in boiling D-limonene to collect the residualpolymer coated on the yarn. This D-Limonene can be recombined with themain polymer solution filtrate for devolatilization to achieve higherpolymer yield overall.

The collected polymer solution in the flask was again placed back ontothe heating mantle to devolatilize. The air was also purged from theflask again using CO₂ gas prior to re-heating the sample. With the CO₂blanket in place, the sample was again heated to nearly boiling. Whenthe CO₂ blanket began to push out of the container by the D-limonenevapor, a condenser and solvent recovery apparatus was connected to theflask to collect the distilled D-limonene from the flask. The sample washeated slowly while the majority of the D-limonene distilled out of theflask and the heat was gradually increased as the volume of liquid inthe flask reduced. This was continued until the stir bar nearly orcompletely stopped spinning due to the viscosity increase and solventremoval. Once no more solvent was being devolatilized, the heat sourcewas removed. Utilizing the same or similar process described above inconnection with the control sample, the recovered polymer componentswere cooled and vacuum dried to at least substantially remove remainingresidual solvent from the sample.

Once the recovered polymer samples were cooled, the recovered polymercompositions were tested for Melt Flow Rate properties. The resultingmelt flow rates are set forth in Table 4 below:

TABLE 4 Melt Flow Properties of Reclaimed Samples 1-8 Recovered Sample 165.79 g/10 min. Recovered Sample 2 53.96 g/10 min. Recovered Sample 346.04 g/10 min. Recovered Sample 4 45.60 g/10 min. Recovered Sample 540.74 g/10 min. Recovered Sample 6 41.22 g/10 min. Recovered Sample 740.56 g/10 min. Recovered Sample 8 41.42 g/10 min. Average of RecoveredSamples 1-8 46.92 g/10 min.

When compared to the initial melt flow characteristics of the virgincontrol samples set forth in Table 1 above, the results of the melt flowrates for these recovered samples indicate that the recovered polymerfrom the actual carpet composition exhibits similar processingcharacteristics to that of virgin adhesive composition and can thereforebe used as a recycled component in a second generation adhesivecomposition.

Utilizing the same experimental procedures set forth above in Example 2,the melt flow properties of three additional samples were measured toevaluate the reproducibility and reliability of the melt flow propertiesachieved for polymer compositions reclaimed from the actual carpetsamples. The melt flow rates of the three additional samples were eachmeasured four separate times (A-D) and according to the procedures ofASTM D1238-04C. The melt flow data for these additional three samplesare set forth in TABLE 5 below:

TABLE 5 Melt Flow Properties of Reclaimed Samples 9-11 Recovered Sample9-A 44.38 g/10 min. Recovered Sample 9-B 42.57 g/10 min. RecoveredSample 9-C 44.18 g/10 min. Recovered Sample 9-D 46.37 g/10 min.Recovered Sample 10-A 37.44 g/10 min. Recovered Sample 10-B 38.10 g/10min. Recovered Sample 10-C 38.09 g/10 min. Recovered Sample 10-D 37.05g/10 min. Recovered Sample 11-A 46.18 g/10 min. Recovered Sample 11-B44.47 g/10 min. Recovered Sample 11-C 41.63 g/10 min. Recovered Sample11-D 44.62 g/10 min. Average of Recovered Samples 9-11 42.09 g/10 min.

What is claimed is:
 1. A method of making a carpet, comprising the stepsof: providing a greige good comprised of a primary backing and aplurality of carpet fibers, the plurality of carpet fibers penetrating abottom surface of the primary backing and protruding therefrom a topsurface of the primary backing; providing an adhesive polymercomposition comprising a recycled polymer composition, wherein therecycled polymer is reclaimed from a carpet by a method comprising: a)contacting a carpet with a solvent system comprising a terpene; b)dissolving at least of a portion of the polymer composition in thesolvent system to provide a solution of terpene and a dissolved polymer;and c) separating terpene from the solution of terpene and the dissolvedpolymer to provide the reclaimed polymer composition; and applying theadhesive polymer composition to the bottom surface of the primarybacking.
 2. The method of claim 1, wherein the recycled polymer is apolyolefin.
 3. The method of claim 2, wherein the reclaimed polyolefincomposition comprises at least one of a HDPE, LDPE, LLDPE, ULDPE, VLDPE,VLLDPE, copolymer of ethylene and alpha olefin, polypropylene, copolymerof propylene and alpha olefin, copolymer of propylene and ethylene, EVA,and EMA.
 4. The method of claim 1, wherein the applied adhesivecomposition comprises a blend of the reclaimed polyolefin compositionand a virgin polyolefin composition.
 5. The method of claim 4, whereinthe virgin polyolefin composition comprises at least one homogenouslybranched ethylene polymer characterized as having a short chainbranching distribution index (SCDBI) of greater than or equal to 50%. 6.The method of claim 1, wherein the applied adhesive compositionsubstantially penetrates and substantially consolidates the fibers. 7.The method of claim 5, wherein the at least one homogeneously branchedethylene polymer is further characterized as having a singledifferential scanning calorimetry, DSC, melting peak between −30 and150° C.
 8. The method of claim 5, wherein the at least one homogeneouslybranched ethylene polymer is homogenously branched linear ethylenepolymer.
 9. The method of claim 1, wherein the primary backing is awoven primary backing.
 10. The method of claim 1, wherein the primarybacking is a nonwoven primary backing.
 11. The method of claim 1,wherein the plurality of carpet fibers comprises a plurality of yarns.12. The method of claim 1, wherein the carpet fibers are selected from agroup consisting of nylon, polypropylene, polyethylene, polyester,acrylics, polyamide, wool, cotton, rayon, and combinations thereof. 13.The method of claim 1, wherein the primary backing is selected from agroup consisting of nylon, polypropylene, polyethylene, polyester,acrylics, polyamide, fiberglass, wool, cotton, rayon, and combinationsthereof.
 14. The method of claim 1, wherein the primary backing consistsessentially of a polypropylene material.
 15. The method of claim 1,further comprising applying a pre-coat material to the backside of thegreige good before applying the adhesive composition.
 16. The method ofclaim 15, wherein the precoat material is selected from a groupconsisting of EVA hotmelt, VAE emulsion, carboxylated styrene-butadiene(XSB) latex copolymer, SBR latex, BDMMA latex, acrylic latex, acryliccopolymer, styrene copolymer, polyolefin hotmelt, polyolefin dispersion,butadiene acrylate copolymer, and combinations thereof.
 17. The methodof claim 1, further comprising applying a secondary backing material toa surface of the applied adhesive backing composition.
 18. The method ofclaim 17, wherein the secondary backing material is woven.
 19. Themethod of claim 17, wherein the secondary backing material is nonwoven.20. The method of claim 17, wherein the secondary backing material isselected from a group consisting of polypropylene, polyethylene, andcombinations thereof.
 21. The method of claim 17, wherein the secondarybacking material comprises at least one homogenously branched ethylenepolymer characterized as having a short chain branching distributionindex (SCDBI) of greater than or equal to 50%.
 22. The method of claim17, further comprising applying a pre-coat material to the backside ofthe greige good before applying the adhesive composition.
 23. The methodof claim 22, wherein the precoat material is selected from a groupconsisting of EVA hotmelt, VAE emulsion, carboxylated styrene-butadiene(XSB) latex copolymer, SBR latex, BDMMA latex, acrylic latex, acryliccopolymer, styrene copolymer, polyolefin hotmelt, polyolefindispersions, butadiene acrylate copolymer, and combinations thereof.